Guidance notes on the design, construction, approval and ...

Technical Services Partnership Witham Park House Waterside South, Lincoln, LN5 7JN Tel CSC: (01522) 782070 Fax: (01522) 516716 E-mail: [email protected]

Guidance notes on the design, construction, approval and drawing standards for projects

on Lincolnshire highways

LincolnshireCOUNTY COUNCIL


HIGHWAYS ALLIANCE

Note: This information is held digitally in a live time system. If you are reading this on printed media, there is a risk it may not be current. Please check for updates.

Summary of Contents

General Introduction Roads Structures Street Lighting Traffic Signals Signs & Lines

Cross Discipline Topics Drawing Standards (NB Detail not included in CPO information as not relied on for design) CAD User Guide (NB Detail not included in CPO information as not relied on for design) Road Safety Audits

Exception Reports Departures from Standard Traffic Regulation Orders Considerations in Design Typical Details Site Supervision (NB Detail not included in CPO information as not relied on for design) Considerations in Construction (NB Detail not included in CPO information as not relied on for design)

http://www.lincolnshire.gov.uk/typical-details-for-highway-works/65324.article


General Introduction

This design Guide is intended to provide guidance on the design and

construction of highways within Lincolnshire. It is intended that this document is for the use of anyone involved in this type of work.

This is a live document and is held electronically – if you are reading this on

printed media there is a risk it may not be current. Please check for updates.

Technical Services Partnership Roads Design Guide




HIGHWAYS ALLIANCE

Roads Contents

INTRODUCTION AND BACKGROUND

Definitions

HIGHWAY DESIGN

Junction Design

Highway Alignment

Horizontal Design Vertical Design

Design of Roundabouts

Design of Mini Roundabouts

Design of Footways

Design of Cycleways

Highway Construction

Highway Drainage Design – Sealed

Design of Bus Stops

SURVEY EQUIPMENT CALIBRATION

OTHER SOURCES OF INFORMATION



Introduction and Background

Introduction The TSP Roads Team Design Guide has been produced to provide help with the selection of the appropriate design standards for the projects being undertaken within Technical Services Partnership. It is not intended for the guide to replace any of the standards that the County Council has adopted, but it will provide guidance on their application. The guide has been broken down into sections: - Surveys (Data Gathering) Highway Design Preparation of Contracts Statutory Processes This document is a live publication and is only current at the time of use. The user should not print off copies of any of the guidance notes and continue to refer to them, but rather should access the information as new from the web based master copy.

Background The guide has been developed from the original work instructions first developed some years ago. Once the subject covered has been introduced into the guide the relevant work instruction will be withdrawn. All copies held by users of the work instructions should be destroyed. HAT 34, defines the Principal Documents used by the County Council in controlling the standards used in the design of schemes.

Back to contents page

http://george/manual.asp?catId=27480



Definitions

HIGHWAY – the public road system including all elements that makes the system safe

and usable including bridges, lighting, drainage, signing and markings etc ROAD – the adopted carriageway and associated footways ESTATE ROAD – a carriageway constructed by a private concern on private land normally

with a view to it being adopted DRAINAGE SYSTEM – a combination of a number of drain runs and chambers to remove

rain water from a large or complex area DRAINAGE – the provision of localised drainage such as a gully and outfall pipe CAD – computer aided design / drafting [Note: “aided”, computers do not design or draw,

they only aid the user] S38 – a legal agreement between the Highway Authority and a private developer to enable

an estate road to be adopted S278 – a legal agreement between the Highway Authority and another party to enable

work to be done within the Highway that will be to the benefit of both the public and the other party




Highway Design

Junction Design Author R. D. May

Scope The guide covers all aspects of junction design, including the design of simple major/minor priority junctions through to grade separated junctions. It does not cover the design of roundabouts or signalised junctions. Standards Subject to the contents of HAT 34 the following standards may be applicable, the latest version of which should be useless otherwise stated. (NOTE: Documents not contained in HAT 34, such as new standards, may be of relevance to some schemes.)

TD9 Highway link Design link to document

TD42 Major/Minor junctions link to document

TD22 Layout of Grade Separated Junctions link to document

TD40 Layout of Compact Grade Separated Junctions link to document

Development Road Guide link to document

Disability Advice link to document

TD41 Access on to Trunk Roads [junctions below 500AADT] link to document

HAT 30 County Council policy on Cycle provision link to document Application All junctions shall where practical comply with the relevant standards set out above. For all principal and classified (non estate roads) junctions should be designed to conform to the standards set out in TD9, TD42, TD22, TD40 and TD41 as appropriate. For estate roads the standards set out in the development road guide shall be used. The designer should note that where the estate makes a junction with the classified road network it should be designed in accordance with TD42 or other relevant national guidance and not to the development road guide.

http://www.standardsforhighways.co.uk/dmrb/vol6/section1.htm




http://www.lincolnshire.gov.uk/section.asp?sectiontype=listmixed&catid=28716

http://www.dft.gov.uk/transportforyou/access/peti/inclusivemobility





Notes/Guidance

Designers will need to take into account the following: -

TD42 or any of the other TDs should not be read in isolation. TD9 gives a great deal of guidance on the application of design standards and the various criteria that need to be considered.

Adequate visibility is crucial to the safe operation of any junction, too great a visibility can have a detrimental impact. Particular note should be paid to TD9 paragraph 1.26.

TD42, as with many of the national design guides, focuses on the design of the carriageway for motorised traffic and pays little attention to other road users such as pedestrians and cyclists. The designer will need to consider whether the junction is likely to be used by cyclist and/or pedestrians and if so the likely level of usage that will need to be taken into account.

Particular attention to the provision of safe crossing points, especially for the less able needs to be considered. The crossing points should be located as near to the desired lines as possible. Location away from the desired lines will reduce the effectiveness of the provision.

The designer should always consider the capacity of the junction at the time of construction, but also will need to take into account future traffic demands. Guidance on the choice of junctions is set out in TD42 and TD 41. If capacity is an issue then layout capacity should be tested using PICADY, a programme that will calculate the capacity of a junction.

Many junctions will reside on abnormal road routes. Reference to TSP structures section should be made before finalising any design options.

Advice should be requested from specialist engineers regarding lighting, signs etc.




Highway Alignment Author: R. D. May

Scope The Design guide covers the design of the horizontal and vertical alignment of carriageways. Standards Subject to the contents of HAT 34 the following standards may be applicable, the latest version of which should be useless otherwise stated. (NOTE: Documents not contained in HAT 34, such as new standards, may be of relevance to some schemes.)


Development Road Specification link to document


Guidance on the use of Tactile Paving Surfaces link to document

HAT 30 County Council policy on Cycle provision link to document

TD27 Cross-Sections and Headrooms link to document Application The horizontal and vertical alignment of links (the section of carriageway between junctions) shall comply where possible with the relevant standards set out above. For all principal and classified (non estate roads) all links should be designed to conform to the standards set out in TD9. Further guidance is given in the Maintenance Manual and is applicable to minor improvements of existing roads. For estate roads the standards set out in the development road guide should be used. The designer should note that where the development forms an improvement of the existing classified road network it shall be designed in accordance with TD9 and not to the development road guide.




https://www.gov.uk/government/publications/guidance-on-the-use-of-tactile-paving-surfaces





Notes/Guidance Designers will need to take into account the following: -


Adequate visibility is crucial to the safe operation of any highway. Particular note should be paid to TD9 paragraph 1.26.

TD9, as with many of the national design guides, focuses on the design of the carriageway for motorised traffic and pays little attention to other road users such as pedestrians and cyclists. The designer will need to consider whether the links are likely to be used by cyclists and/or pedestrians and if so the potential level of usage that will need to be taken into account.

Particular attention to the provision of safe crossing points, especially for the less able needs to be considered. The crossing points should be located as near to the desire lines as possible. Location away from the desire lines will reduce the effectiveness of the provision.

The designer should always consider the capacity of the links, both at time of construction, but also will need to take into account future traffic demands.

Many links will form part of abnormal road routes. Reference to TSP structures section should be made before finalising any design.

Advice should be requested from specialist engineers regarding lighting, signs etc.

Horizontal Design

Whilst the design of an arc can be simple, most alignments will require the application of transitions. Use of transitions will have a significant impact upon the plan location of the arc. This is an important consideration especially when assessing the feasibility of an alignment. In most cases initial alignments should be manually designed and developed using MX design software. Layouts drafted in AutoCad are not generally adequate and should be used only where the alterations are minor. Manual design can be appropriate in some cases, certainly initially. REMEMBER, the final horizontal design must tie in with the existing alignments at either end regardless of the effect this has on the new design.



Vertical Design

MX uses the M value in calculating the vertical alignment of the carriageway. TD9 uses K values. K = L/(a-b) where L is the length of the vertical curve, a = the gradient at the start of the vertical curve (expressed as a percentage) and b = the gradient at the end of the vertical curve (expressed as a percentage). M = 100/K For example TD9 gives the minimum crest K value for stopping sight distance (SSD) of a 100 kph road as 100. Therefore: - M = 100/K = 100/100 = 1 Manual design can be appropriate in some cases, certainly initially. REMEMBER, the final vertical design must tie in with the existing alignments at either end regardless of the effect this has on the new design.




Design of Roundabouts Author: R. D. May

Scope The guide covers all aspects of roundabout design, excluding the design of mini roundabouts. Standards Subject to the contents of HAT 34 the following standards may be applicable, the latest version of which should be useless otherwise stated. (NOTE: Documents not contained in HAT 34, such as new standards, may be of relevance to some schemes.)


TD16 Geometric Design of Roundabouts link to document



HAT30 County Council policy on Cycle provision link to document Application All roundabouts should comply with the standards set out above. S278 schemes shall also be subject to these standards unless a relaxation or departure is approved. Notes/Guidance Designers will need to take into account the following: -


Adequate visibility is crucial to the safe operation of any roundabout, too great a visibility can have a detrimental impact. Particular note should be paid to TD9 paragraph 1.26.

TD16, as with many of the national design guides, focuses on the design of the carriageway for motorised traffic and pays little attention to other road users such as pedestrians and cyclists. The designer will need to consider whether the









roundabout is likely to be used by cyclists and/or pedestrians and if so the likely level of usage that will need to be taken into account.


The designer should always consider the capacity of the junction, both at time of construction, but also will need to take into account future traffic demands. Guidance is set out in TD16. If capacity is an issue then layout capacity should be tested using ARCADY, a programme that will calculate the capacity of a Roundabout.

Many roundabouts will reside on abnormal road routes. Reference to TSP structures section should be made before finalising any design options.

Roundabouts will only operate safely if the geometric properties restrict the vehicle speeds at entry. Deflection requirements shall apply to all roundabout approaches; this is because it is essential to regulate vehicle speed before entry and not whilst on the roundabout.

As a general rule it is difficult to achieve adequate deflection on roundabouts of less than 40m diameter (single carriageway approaches) and 80m (dual carriageway approaches).

Landscape designers are particularly keen to plant up the centre of roundabouts. Designers must ensure that the mature size of and proposed planting is taken into account to ensure that the planting does not encroach into the visibility envelopes. Works of art, particularly mobile features should not be sited on the central islands as these can easily distract drivers.

Safety fencing and signing should be sited with care to ensure that sight lines are not obstructed.

Care will need to be taken with the design of the vertical alignment. Designers should be aware that sudden/steep changes in gradient are a major contributory factor to accidents at roundabouts, particular affecting large vehicles. No change in grade shall be greater than 5%.




Design of Mini Roundabouts Author: R. D. May

Scope The guide covers all aspects of mini roundabout design. The design of conventional roundabouts is dealt with in D103.01 Standards Subject to the contents of HAT 34 the following standards may be applicable, the latest version of which should be useless otherwise stated. (NOTE: Documents not contained in HAT 34, such as new standards, may be of relevance to some schemes.)


TD16 Geometric Design of Roundabouts link to document

TD54 Design of Mini-Roundabouts link to document

Mini Roundabouts Good Practice Guide (MRGPG) link to document



HAT30 County Council policy on Cycle provision link to document Application All roundabouts should comply with the standards set out above. S278 schemes shall also be subject to these standards unless a relaxation or departure is approved. Mini roundabouts shall not be used on roads that have a speed greater than 30mph. Notes/Guidance Designers will need to take into account the following: -

TD54, Mini Roundabouts Good Practice Guide and TD16 or any of the other TDs should not be read in isolation. MRGPG and TD9 gives a great deal of guidance on the application of design standards and the various criteria that need to be considered.




https://www.gov.uk/government/publications/mini-roundabouts







Adequate visibility is crucial to the safe operation of any roundabout, too great a visibility can have a detrimental impact. Particular note should be paid to TD9/93 paragraph 1.26.

TD54, MRGPG and TD16, as with many of the national design guides, focuses on the design of the carriageway for motorised traffic and pays little attention to other road users such as pedestrians and cyclists. The designer will need to consider whether the roundabout is likely to be used by cyclists and/or pedestrians and if so the likely level of usage that will need to be taken into account.


The designer should always consider the capacity of the junction, both at time of construction, but also will need to take into account future traffic demands. Guidance is set out in TD16. If capacity is an issue then layout capacity should be tested using ARCADY, a programme that will calculate the capacity of a Roundabout.

Mini roundabouts may reside on abnormal road routes. Reference to TSP structures section should be made before finalising any design options.

Mini roundabouts will only operate safely if the geometric properties restrict the vehicle speeds at entry, deflection is key to ensuring that the roundabout works safely. This can be difficult to achieve due to the nature of the sites that are usually put forward for mini roundabouts. However, the designer should always try to induce some form of deflection if at all possible.

The layout of mini roundabouts needs to be visible to the user.

Safety fencing, guard railing and signing should be sited with care to ensure that sight lines are not obstructed.

Care will need to be taken with the design of the vertical alignment. Designers should be aware that sudden/steep changes in gradient are a major contributory factor to accidents at roundabouts, particular affecting large vehicles.




Design of Footways Author: R. D. May

Scope The design guide covers the design of new footways. Standards Subject to the contents of HAT 34 the following standards may be applicable, the latest version of which should be useless otherwise stated. (NOTE: Documents not contained in HAT 34, such as new standards, may be of relevance to some schemes.)

Maintenance Design Manual link to document



Development Road Specification link to document Application All footways should comply with the standards set out above. For all existing county roads they shall be designed to conform to the standards set out in the Highways Maintenance Design Manual, the use of tactile pavements and the County Council policy on Cycle provision (HAT 30). For estate roads the standards set out in the development road guide shall be used. Notes/Guidance Designers will need to take into account the following: -

Where possible footways should be located to the back of the verge, with a minimum gap of 1.0m between the carriageway and the footway. Smaller gaps pose an increased safety risk and it is difficult to establish a good growth of grass due to the effects of de-icing salts and poor drainage. Narrower widths should be filled with a suitable material such as block paving.

The designer will need to consider whether the footway is likely to be used by the disabled and if so the level of usage that will need to be taken into account. This may impact upon footway widths and safety provision e.g. tactile paving.

http://george/section.asp?catId=10731






All footways should have concrete edgings, however, see Highway Maintenance Design Guide.

Footways should be designed to drain away from adjoining properties unless there is suitable drainage provided.

Traditionally footways have been designed with a 1 in 30 crossfall. Current guidance recommends that 1 in 40 be used, especially where use by the disabled (e.g. electric buggies) is likely to be a regular occurrence.

Longfall should be limited to no greater than 1 in 14.

The crossing of private accesses can cause difficulties Whilst in ideal circumstances the footway levels should not need alteration from a smooth line to cross accesses this may not be possible. In such circumstances levels should not: -

i. form a switchback profile ii. produce changes in gradient that could cause a risk of grounding vehicles.

Details of footway construction can be found in the Maintenance Design Manual and in the TD/5 series of typical details.

Care should be taken with the choice of footway materials. Designers should ensure that materials have a good slip resistance. Falls can occur when adjacent materials have different resistance to slipping. This can be a problem when working with natural materials especially when they are being specified for their aesthetic appearance rather than their physical properties.

Remember that any new footway facility must fit into the existing situation even if this does require Departure from Standards.



http://www.lincolnshire.gov.uk/typical-details-for-highway-works/65324.article



Design of Cycleways Author: R. D. May

Scope The design guide covers the design of new cycleways and the improvement of existing facilities. Standards

Subject to the contents of HAT 34 the following standards may be applicable, the latest version of which should be used unless otherwise stated. (NOTE: Documents not contained in HAT 34, such as new standards, may be of relevance to some schemes.)

Maintenance Design Manual link to document



Development Road Specification link to document Application All Cycleways should comply with the standards set out above. For all existing county roads they should be designed to conform to the standards set out in the Highways Maintenance Design Manual, the use of tactile pavements and the County Council policy on Cycle provision (HAT 30). For estate roads the standards set out in the development road guide should be used. Notes/Guidance Designers will need to take into account the following: -

Where possible cycleways should be located to the back of the verge, with a minimum gap of 1.0m between the carriageway and the footway. Smaller gaps pose an increased safety risk and it is difficult to establish a good growth of grass due to the effects of de-icing salts and poor drainage. Narrower widths should be filled with a suitable material such as block paving.

All cycleways should have concrete edgings.








Cycleways should be designed to drain away from adjoining properties unless there is suitable drainage provided.

The crossing of private accesses can cause difficulties. Whilst in ideal circumstances the cycleway levels should not need alteration from a smooth line to cross accesses this may not be possible. In such circumstances levels should not:-

i. form a switchback profile ii. produce changes in gradient that cause the risk of grounding vehicles.

Details of cycleway construction can be found in the maintenance manual and in the kerbs, footways and paved areas series of typical details.

Obstructions such as Bollards and signs and lighting columns should be avoided. Where an existing footway is being upgraded existing street furniture is frequently a problem and should be moved if possible. The designer must ensure that the owner of the street furniture is made aware of its removal and that any necessary replacements are provided.

Segregation of cyclists and pedestrians should be considered whenever possible, but the hierarchy included within the county council's cycle design guide not be considered.

Where cycle lanes on existing carriageways are required the designer will need to establish whether the lane is mandatory or advisory. Mandatory lanes will require a Traffic Regulation Order.



http://www.lincolnshire.gov.uk/kerbs-footways-and-paved-areas/59419.article

../TROs.doc



Highway Construction Author: P. A. Saxby

Scope The Design guide covers the design of the construction of carriageways. Standards Subject to the contents of HAT 34 the following standards may be applicable, the latest version of which should be useless otherwise stated. (NOTE: Documents not contained in HAT 34, such as new standards, may be of relevance to some schemes.)

Development Road Specification link to document

LCC Maintenance Design Manual link to document

IAN73/06 Design Guidance for Road Pavements link to document

HD26 Pavement Design link to document

HD36 Surfacing Materials for New and Maintenance Construction link to document Application The construction of the carriageway shall where possible comply with the relevant standards set out above. Generally:

Main roads improvements, including S278s, are designed to the HA design guides

– IAN73/06, HD26 and HD36.

Estate roads are designed to the Development Road Specification.

Maintenance works are designed to the Maintenance Design Manual.

However, requirements are scheme specific and may need to be confirmed by the

client or Divisional Highway Manager as appropriate.

Notes/Guidance Designers will need to take into account the following: -

No design guidance should be read in isolation. Back to contents page



http://www.dft.gov.uk/ha/standards/ians/index.htm





Highway Drainage Design – Sealed Author: N. Whitfield Scope There are two elements to highway drainage design, surface and sub-surface systems. This guide is only applicable to surface systems. Lincs Lab should be consulted with respect to sub-surface drainage. Standards The following standards will apply: - (Those publications in italics are those commonly used.) Development Road Specification and Construction Guide link to document Maintenance Design Manual link to document HA 37 Hydraulic Design of Road Edge Surface Water Channels link to document HA 39 Edge of Pavement Details link to document HA40 Determination of Pipe and Bedding Combinations for Drainage Works link to

document HA 41 A/90 A Permeameter for Road Drainage Layers link to document HA 71 withdrawn – Refer to HD 45/09 link to document HA 78 Design of Outfalls for Surface Water Channels link to document HA 79 Edge of Pavement Details for Porous Asphalt Surface Courses link to document HA 83 Safety Aspects of Road Edge Drainage Features link to document HA 102 Spacing of Road Gullies link to document HA 103 Vegetative Treatment System for Highway Runoff link to document HA 104 Chamber Tops and Gully Tops for Road Drainage and Services: Installation and

Maintenance link to document HA 105 Sumpless Gullies link to document HA 106 Drainage Runoff from Natural Catchments link to document



















HA107 Design of Outfall and Culvert Details link to document HA113 Combined Channel and Pipe System for Surface Water Drainage link to document HA118 Design of Soakaways link to document HA119 Grassed Surface Water Channels for Highway Runoff link to document HD 33 Surface and Sub-surface Drainage Systems for Highways link to document TA 80 Surface Drainage of Wide Carriageways link to document Relevant British Standards The following documents offer good advice, but it is not an exhaustive list: CIRIA 635 Design for Exceedance in Urban Drainage link to document CIRIA 697 The SUDS Manual link to document CIRIA 698 Site Handbook for the Construction of SUDS link to document Design and Analysis of Urban Storm Drainage; Volumes 1 – 4; The Wallingford Procedure

link to information Sewers for Adoption link to information Application All surface drainage systems whether they are for development roads, new works (bypasses etc.) or maintenance works where the Highway Authority is the client. Development roads shall comply with the standards set out in the Development Road Specification and Construction Guide. Maintenance (minor improvements to existing infrastructure) shall comply with the standards set out in the Maintenance Design Manual. All other works shall be designed in accordance with the relevant standards contained in the Design Manual for Roads and Bridges. Drainage systems for other authorities will be designed in accordance with their requirements. Notes/Guidance







http://www.ciria.org/service/My_Account/AsiCommon/Controls/Shared/FormsAuthentication/Login.aspx



http://books.hrwallingford.co.uk/acatalog/d_page_4.html#aWP5_20CD

http://sfa.wrcplc.co.uk/



The three major objectives for draining highways are: 1. The rapid removal of surface water allowing the safe passage of vehicles with minimal

nuisance; 2. To maximise the longevity of the pavement structure and associated earthworks; 3. To minimise the impact of surface water run-off on the receiving environment. Designers will need to take into account the following:

Design guidance particularly the advice in the Design Manual for Roads and Bridges which should not be read in isolation.

Check you have an outfall and confirm the ownership and any discharge restriction.

Consider how the drainage system will be maintained – i.e. personnel access, vehicle access for off highway drainage, traffic management

Any works within 9m of Environment Agency infrastructure requires their written consent.




Design of Bus Stops Author: M. Wilson Scope The design guide for bus stops has been produced by Transport Services – link to document.



Survey Equipment Calibration Author: R.D. May

Scope The calibration of equipment is an essential part of the system to meeting the requirements of the QMS. Standards Subject to the contents of HAT 34 the following standards may be applicable, the latest version of which should be useless otherwise stated. (NOTE: Documents not contained in HAT 34, such as new standards, may be of relevance to some schemes.)

Survey Store Database link to document Application The dates of due calibration are all recorded within the Survey Store Database. The responsible person shall check (on a monthly basis) for equipment due for calibration. Appropriate action shall then to be taken to ensure that re calibration is carried out, before the current certification expires. Notes/Guidance Total Stations shall be sent away for calibration to: -


../../DOCUMENTS/Survey%20Store.xls



OTHER SOURCES OF INFORMATION

• Transport Advice Portal link to site • Local Transport Notes link to site 2/09 Pedestrian Guardrailing 1/09 Signalised Roundabouts 3/08 Mixed Priority Routes 2/08 Cycle Infrastructure Design 1/08 Traffic Management & Streetscape 1/07 Traffic Calming 2/95 Design of Pedestrian Crossings • Traffic Advisory Leaflets link to site 2/09 Integration of Pedestrian Traffic Signal Control within SCOOT-UTC Systems 1/09 Compact MOVA 1/08 Wig-wag Signals 2/07 Use of Bus Lanes by Motorcycles 3/06 High Occupancy Vehicle Lanes • Traffic Management Act link to site • Parking and Traffic Regulation link to site • Street Works link to site • Good Practice Guidance link to site Puffin Crossings Mini-roundabouts Portable Vehicular Signals • Traffic Signs and Signals Traffic Signs Manual Working Drawings for Traffic Signs Traffic Signs Image Database • Urban Traffic Management and Control link to site • Manual for Streets link to site • Home Zones link to site Standard Drawing Link to Site


http://www.tap.iht.org/

https://www.gov.uk/government/publications/local-transport-notes

https://www.gov.uk/government/organisations/department-for-transport/series/traffic-advisory-leaflets

http://www.legislation.gov.uk/ukpga/2004/18/made

https://www.gov.uk/search?tab=government-results&q=parking+and+traffic+regulation#services-information-results

https://www.gov.uk/government/publications/street-works-register

http://www.dft.gov.uk/roads/tss/gpg

http://webarchive.nationalarchives.gov.uk/20120606202951/http:/www.dft.gov.uk/publications/puffin-crossings


https://www.gov.uk/government/publications/departmental-guidance-to-local-councils-highways-agency-concerning-road-traffic-light-signals

https://www.gov.uk/government/publications/traffic-signs-manual

https://www.gov.uk/working-drawings-for-traffic-signs

https://www.gov.uk/traffic-sign-images

http://www.utmc.uk.com/

http://www.dft.gov.uk/mfs

http://www.dft.gov.uk/homezones

http://www.lincolnshire.gov.uk/section.asp?catid=15443&docid=65324



HIGHWAYS ALLIANCE


Structures Content

Abnormal Loads (NB Detail not included in CPO information as not relied on for design)

Guidance Document Appendices A Typical Memo – Chief Constable B Typical Memo – Chief Constable C Letter to Haulier D Letter to Haulier E Form of Indemnity F Letter to Vehicle Certification Agency G Process H A Brief Guide to the Law on the Road Use of Abnormal Load Carriers

and Mobile Engineering Plant I Background and definitions (DfT)

Weight Restrictions (NB Detail not included in CPO information as not relied on for design) County Council Policy Legal Obligations Types of Weight, Height and Width Restriction Regulatory Signs and Permitted Variants

Design of Small Highway Structures Guidance notes on the design, approval, construction and adoption of small

highway structures within Lincolnshire Highways

1. Introduction 2. Design And Technical Approval 3. Other External Constraints 4. Basic Design Considerations 5. Specification 6. Culverts 7. Retaining Walls 8. Footbridges 9. Road Restraint Systems 10. As Built Drawings And Maintenance Manual Appendices A Key Documents (Code of Practice And Design Documents) B Technical Approval Requirements C Construction Tolerances

Design of Vehicle Restraint Systems Guidance on the specification of VRS on Lincolnshire Highways

small highway structures

DESIGN GUIDE

Guidance notes on the design, approval, construction and adoption of small highway

structures within Lincolnshire highways

Technical Services Partnership

Witham Park House

Waterside South,

Lincoln, LN5 7JN

Tel CSC: (01522) 782070

Fax: (01522) 516716

E-mail:

Revised: January 2010

SMALL HIGHWAY STRUCTURES Design, Construction And Technical Approval Guidance Notes

Contents

1. Introduction 2 1

2. Design And Technical Approval 4

3. Other External Constraints 5

4. Basic Design Considerations 6

5. Specification 8

6. Culverts 10

7. Retaining Walls 14

8. Footbridges 16

9. Road Restraint Systems 17 14

10. As Built Drawings And Maintenance Manual 19

Appendices

A Key Documents (Codes Of Practice And Design Documents) 20

B Technical Approval Requirements 22

C Construction Tolerances 23


1.3. These notes are prepared to offer

guidance and assistance to external

organisations wishing to undertake

alterations to existing structures or

construction of new structures.

The guidance provides the guidelines for the

design and specification of small highway

structures. They are not exhaustive and

should not be treated as such. They should

be read in conjunction with the Lincolnshire

County Council “Development Road Layout

Guide and Specification” document.

The notes apply in whole to structures to be

adopted by the County Council, and in part to

structures which carry or support the

highway, but are not to be adopted (see

Section 10).

1.4. The Construction (Design and

Management) Regulations 1997 lay out

requirements for clients, CDM co-ordinators

and designers to be satisfied as to their

competence to perform the functions

required of them, and to make adequate

resources available to meet their duties

under Health and Safety Statutory

provisions.

1.1. Lincolnshire County Council, as

Highway Authority within the County are

responsible for the construction,

maintenance and repair of the majority of

highway structures. Any new structures,

additions or alterations to structures located

within the public highway network will require

the prior approval of Lincolnshire County

Council, regardless of present or future

ownership.

For the purpose of this document, a highway

structure is defined as any item of

infrastructure providing either a clear span or

retained height of 600mm or greater. This

encompasses bridges, culverts (both pipes

and concrete boxes), footbridges and

retaining walls.

1.2. The management of Lincolnshire

highway structures is undertaken by

Technical Services Partnership on behalf of

Lincolnshire County Council, all

correspondence should be addressed to:

Technical Services Partnership

Lincolnshire County Council

Witham Park

Waterside South

Lincoln

LN5 7JN

Trunk Roads are controlled by the Highways

Agency, and matters relating to these roads

must be referred to this organisation.

1. Introduction


1.5. All new structures that are adopted as

public highway will require a commuted sum

to be paid to the authority for the future

inspection, maintenance and replacement of

the structure.

This commuted sum will be calculated to

cover the costs associated with the

maintenance of the structure over the next

150 years, discounted for the effects of

inflation and interest payments, and may be

significant compared to the construction cost

of the structure. The calculation of this

commuted sum will be generally in

accordance with CSS guidelines.

1.6. Any changes to the highway layout will

be subjected to a safety audit process, at

both the design and construction stages. This

will be undertaken by the Lincolnshire Road

Safety Partnership, and any matters arising

must be either attended to in the design, or

an exception report approved.

1.7. For non-adoptable small highway

structures the Highway Authority (the County

Council) is more concerned with their

strength and integrity than their durability.

The basic design considerations in section

2 apply, however the requirements with

regard to durability may be relaxed. The

requirements in other sections which affect

the strength and integrity of the structure

shall apply. Aspects of the Technical Approval process

may still apply (see paragraph 2.3)


2.1. All structures are to be designed and

drawn by suitably qualified civil engineers

with a working knowledge and experience of

the design of highway structures to current

standards as referred to in Section 4 below.

2.2. Attention is drawn to the requirement

to Construction (Design and Management) Regulations 2007 in relation to assessing the

competence of designers, in both individuals

and organisations.

2.3. Design methods and procedures for

the design of highway structures are

provided in the most recently published

edition of the Highway Agency Design Manual for Roads and Bridges (commonly

referred to as DMRB).

2.4. The technical advice notes and

standards contained in this document are

adopted by Lincolnshire County Council in

their entirety, and further supplemented by

other Lincolnshire specific standards detailed

in appendix ‘A’ and requirements contained

in this document.

2.5. Reference should be made to

Lincolnshire County Council policy document

HAT34 - Design Standards And Departures For Highway Schemes (Improvements, Maintenance And Developments), which

further defines documents and policies

relevant to the design of highway

infrastructure.

2.6. The status of all Highway Agency

published Interim Advice Notes (IAN’s)

should be confirmed with the TAA prior to

their inclusion within the design.

2.7. Authorisation must be obtained from

Technical Services Partnership for all

highway structures prior to commencement of

construction, including those subsequently

offered for adoption. Retrospective approval

may not be granted, and in such situations

Lincolnshire County Council as Highway

Authority may refuse to adopt the structure.

2.8. For non-adoptable highway structures

the Highway Authority will decide what part of

the Technical Approval process will apply,

and this should be confirmed with Technical

Service Partnership.

2.9. Where the appropriate published

standards are not complied with, a Departure

from Standards submission will be required

for endorsement by the Head of Technical

Services. This submission will require the

support of the Structures Group prior to

application for endorsement. Details of the

Departure from Standards submission

process can be supplied by Technical

Service Partnership.

2.10. Designs undertaken to building codes

of practice and standards (in particular

BS8110), will not be approved and will be

returned unchecked.

2. Design And Technical Approval


3. Other External Constraints

3.1. In the case of works to be carried out

in, over or adjacent to any watercourse, the

design must also be submitted to any

affected drainage authority for approval. Prior

agreement must be sought to any attached

conditions that may subsequently be

transferred onto the County Council. The

County Council will require proof that this

approval has been granted.

It is considered acceptable for the drainage

authority to request the invert of a structure

to be lowered by up to 150mm when a

structure is reconstructed. Any lowering

greater than this is considered betterment

and a contribution may be requested.

3.2. Certain species of plants and animals

are protected under the Wildlife and

Countryside Acts of 1981 and 1991. The

promoter must be aware of restrictions this

protection may have on undertaking certain

works and should dutifully discharge their

responsibilities and be able to demonstrate

such.

3.3. Many statutory bodies have plant and

equipment located within the public highway

which may affect the construction or

modification works, or affect the final

structure. This includes communication

services, pipelines, sewers and supplies.

Any such services incorporated into an

adopted structure must be installed in such a

manner that the service may be replaced

without alteration to the associated structure.

This is usually achieved with the provision of

service ducts and access chambers,

extending sufficiently beyond the extents of

the structure (including any associated safety

barriers).

Consideration should be given to providing

additional spare ducts for to allow future

services to cross the structure without

alteration. This is of particular importance

where the distance between the structure

and final surface is low.


4. Basic Design Considerations

4.1. The design life for all adoptable

highway structures shall be 120 years. The

DMRB allows the use of ’at least 100 years’

for assessing the durability of concrete

elements in accordance with BS8500 et al.

4.2. In addition to complying with all

appropriate standards listed in appendix ‘A’

the designer must bear the following

additional objectives in mind.

• Safe passage for pedestrians and

vehicles

• minimisation of future maintenance

costs

• minimisation of vandalism risk

• aesthetics and harmony with

surroundings

4.3. All highway structures must be

designed for both ‘full’ HA loading and a

number of units of HB loading in accordance

with BD37. Generally, the number of HB units

appropriate to the design is as shown below,

however this should be agreed with

Technical Services Partnership.

Category ‘HB’ Loading

Major routes 45 units

A & B class

carriageways 37.5 units

Other

carriageways 30 units

4.4. Design calculations must be checked

by an independent person or group prior to

submission for approval (see notes on

technical approval). An appropriate

organisation must be selected based on the

category of structure (see BD2). The checked

calculations must include a commentary by

the checker to indicate the success of the

check.

4.5. Particular care is required when

designing supporting structures for areas

such as footways, verges etc. If there is to

be no physical barrier to prevent vehicles

from gaining access to these areas, retaining

structures must be designed for the

appropriate accidental wheel loading or

surcharge.

For simple analysis of earth pressures on

retaining structures the requirement for the

inclusion of HA and HB loading may be

replaced with a nominal live load surcharge

as BD37/01 paragraph 5.8.2.

4.6. The use of structural elements where

the durability is such that they are unable to

achieve the required 120 year design life will

require the approval of Technical Services

Partnership and will result in a significantly

increased Commuted Sum being payable.

4.7. All drawings submitted for approval

shall have levels related to Ordnance Survey

Datum Newlyn (OSDN).


4.8. The requirement to provide protection

for errant vehicles in the event of an

accident should be assessed wherever:

• the highway cross section is altered

• a new hazard is introduced

• works are undertaken in the vicinity

of an existing road restraint system

which has reached the end of it’s

serviceable life

This assessment should be completed using

the Highways Agency computerised risk

modelling system, the Road Restraint Risk Assessment Process (RRRAP) as

implemented by TD19 where the enforced

speed limit is 50mph or higher and the

annual average daily traffic flow exceeds

5000 vehicles per day.

4.9. In situations outside of the scope of

the above restrictions, a risk assessment

generally in accordance with appendix 2 of

TD19 shall be carried out using Lincolnshire County Council’s Provision Of Vehicle Restraint System (PVRSAS) data sheet. To

obtain this spreadsheet and for guidance on

usage, contact Technical Services

Partnership.

4.10. Where the PVRSAS is used, the

outcome of this assessment must be

submitted to Technical Services Partnership

for agreement.

4.11. The accident data required for the

completion of the PVRSAS is available from:

Lincolnshire Road Safety Partnership

Witham House

The Pelham Centre

Canwick Road

Lincoln

LN5 8HE 4.12. Minor highway structures usually

include items such as columns, gantries,

cantilever masts and high masts for

supporting lighting, signs, traffic signals,

CCTV, safety cameras, communication

equipment and the like.

The design of these structures is covered in

detail in BD94.

Depending upon the size and type of these

structures, elements of the Technical

Approval process may need to be followed

as outlined in appendix ‘B’.

The need for protecting these structures with

an appropriate vehicle restraint system

must be considered.

Careful consideration must be given to

providing access for maintenance and

inspection over the life of the structure, for

both the owner and the highway authority.


5. Specification

5.3.1. Concrete

The minimum requirements for structural

concrete shall be:

• Minimum strength class C32/40

• Minimum cement content 325kg/m3

• Maximum aggregate size 20mm

• Maximum free water cement ratio 0.45

Minimum cover to reinforcement shall be

40mm, including pre-cast concrete elements.

Only 1.2mm diameter stainless steel tie wire

shall be used for tying reinforcement.

All buried concrete services shall receive 2

coats of an approved below ground

waterproofing system.

5.3.2. Parapets

Anti-theft (or anti-vandal) holding down bolts

shall be provided at all vehicular and

pedestrian parapet post locations. An anti-

theft fixing shall be provided for each rail

section.

Anti-climb mesh shall be provided on the face

of post and rail type vehicular parapets

where these are located adjacent to a

footway. This mesh shall be attached in such

a manner as to facilitate simple replacement.

All steel vehicular parapets shall be painted.

5.1. The Specification for the works shall

be the latest published edition of the

Specification for Highway Works (commonly

referred to as SHW) as part of the Highways

Agency Manual Of Contract Documents For Highway Works applied in accordance with

the Notes For Guidance On The Specification For Highway Works, as modified below.

5.2. The SHW requires that items such as

concrete, waterproofing and backfill are

tested by the promoter. Proposals for

material testing items and frequency are to

be agreed with Technical Services

Partnership, and the results supplied in a

timely manner.

Failure to either complete the appropriate

testing or supply the results may affect the

authority’s decision to adopt the structure,

and will invariably lead to an increase in the

commuted sum payable.

5.3. The specification is further enhanced

by the following Lincolnshire County Council

specific additions and minimum

requirements. The requirements of the DMRB

and SHW may exceed this information, in this

instance the latter requirements shall be

complied with.


Coping stones shall be mechanically fixed to

the adjacent structure.

5.3.3. Paint Systems

All protective paint systems shall be

designated for ‘inland difficult access’, with

no maintenance up to 12 years, minor

maintenance after 12 years and major

maintenance after 20 years.

The only colours permitted for protective

systems shall be:

• Green 14C39

• Black 00E53

• Medium Grey 00A09

Other colours and all combinations of colours

will require the approval of Technical

Services Partnership.

5.3.4. Various

Verges shall be hardened over the structure

to the extents of the wing-walls or parapet.

Half battered kerbs shall be provided where a

pedestrian route extends over this hardened

verge otherwise splay kerbs shall be

provided. Kerbs should be installed at

100mm face height. Positive drainage shall

be provided at all kerb faces.

The minimum thickness for any corrugated

steel structure shall be 4mm, and shall be

both galvanised and provided with a

secondary protective coating.

All gabions shall be a minimum of 3.5mm

thick wire and shall be PVC and zinc coated.

Gabions should be hand packed with care

and not machine filled.

Rocker pipes shall be provided on pipe sizes

up to 1800mm DIN where a pipeline enters a

fixed structure. Stub end pipes shall be used

at all ends, cutting of concrete pipes shall not

be permitted.

Red indicator mesh shall be installed directly

above all bituminous additional protective

layers to spray applied waterproofing

systems.

The grading requirement for class 6N

material shall comply with the requirements

for type 1 sub-base material given in table

8/5 in series 800 of SHW. Class 6P material

shall not be permitted.

All timber shall be FSC certified. Only the

following types of timber shall be permitted:

Afrormosia, Afzelia, West African Albizia, Belian, Blackbutt, black Cabbage bark, East African Camphorwood, Curupay African Ebony, Ekki, Greenheart, Guarea, Iroko, Ironbark, Jarrah, Malaysian Kapur, Sabah Kapur, Lapacho, Lignum vitae, Makoré, Mansonia, Mchenga, Muhuhu, Muninga, Nargusta, Okan, Opepe, Andaman Padauk, Burma Padauk, white Peroba, Purpleheart, Pyinkado, Tallowwood, Teak, Rhodesian Teak, Turpentine, Wallaba

Construction tolerances shall be as

appendix ‘C’


6. Culverts

6.1. General

6.1.1. The length of culvert required will be

dictated by the site geometry. Generally the

length must be sufficient to provide level

verges of not less than 2 metres width on

each side of the carriageway. In some cases

it may be preferable to increase the culvert

length to facilitate sloping batters (slope 1:1.5

maximum) and hence reduce the size of

headwalls required, or to construct

revetments.

6.1.2. The length of headwall / wingwalls

must be sufficient to accommodate a 1:1.5

batter from watercourse bed level at the side

of the culvert to verge level at the wall end.

Vertical headwalls and wingwalls should be

designed as free standing retaining walls in

accordance with section 7. Wingwalls may

be parallel to the carriageway or splayed to

suit the site topography.

As an alternative to vertical headwalls, it may

be possible to support the ground above the

structure using a revetment. These are

generally constructed, to a maximum height

of 2m, using broken kerbs and angled at a

maximum of 45°. Stone pitched or sandbag

revetments are not acceptable.

6.1.3. In the vicinity of the wing-walls,

consideration should be given to the

prevention of scour of the bank slopes,

particularly where construction work causes

removal of the natural protection provided by

established vegetation and root systems.

This can be achieved with suitable

revetments, gabions or inclusion of

reinforced soil bank slopes.

6.1.4. The culvert headwall and adjacent

watercourse should be assessed for the need

to provide vehicular containment. Where

vehicular containment is necessary, this

should be provided in accordance with

section 9.

6.1.5. In locations where the appropriate risk

assessment indicates that vehicular

containment is not required, but a pedestrian

route is present a pedestrian parapet will be

provided.

The presence of a cycleway or equestrian

route will require an appropriate increase in

the height of the parapets.

Where there is no clear pedestrian route

(neither a metalled footway nor route of a

public footpath) a white painted hardwood

timber post and two rail fence may be

provided to delineate the headwall location.


As a general rule however in urban or

residential locations all drops will require

either a vehicular or pedestrian parapet.

6.1.6. If parapets or safety barriers will cause

an obstruction to visibility to either vehicles

travelling along the highway or vehicles

emerging from junctions or accesses the

culvert must be lengthened to provide wider

verges. Visibility may be provided over

safety barriers but may not be justified

through either post and rail or vertical infill

parapets.

6.2. Pre-cast Concrete Box Culverts

6.2.1. The design standard for buried

concrete box type structures is BD31. Pre-

cast box culvert units are generally designed

by the manufacturer, to the particular

intensity of highway loading appropriate to

the class of road. The depth of the culvert

below finished road level (F.R.L) must be

considered to determine the appropriate

loadings:

(a) Depth from F.R.L. to top of

culvert unit less than 0.6m:

• HA loading shall consist of the

HA UDL / KEL combination, no

dispersion either load shall be applied

• HB loading appropriate to the

road classification shall be

considered, dispersed through the fill

surfacing material

(b) Depth from F.R.L. to top of

culvert unit 0.6m or greater:

• The appropriate HB loading

only shall be applied

Account shall also be taken of a dispersed

single 100kN HA wheel load where this has a

more severe effect on the structure than the

loads described in (a) or (b) above.

6.2.2. Pre-cast concrete box culvert units on

salted routes must be designed for exposure

classes XC3 and XD2, otherwise an

exposure class of XC3 may be provided.

6.2.3. The bedding for the units is to be in

accordance with Clause 6.2.3 of BD31.

Specific consideration should be given to the

bedding for the units above a headwall base

slab.

6.2.4. If the end units are to be visible on

the completed structure façade, F4 finish fair

faced ends should be provided. The box

culvert units should be jointed and sealed

with an approved low compressibility bitumen

jointing compound, such as Tokstrip.

6.2.5. The top and sides of the units must be

waterproofed with a proprietary approved

waterproofing system down to a level

200mm below the structure soffit and up

100mm onto the headwall, wing-wall or

parapet plinth. A protective layer shall be

provided to the waterproofing system.


6.2.6. Backfilling adjacent to the units is to

comprise suitable granular fill to Clause 610

of the Specification, however only class 6N

material shall be permitted. This material

shall be laid and compacted in accordance

with the Specification.

6.2.7. Fill material within 450mm of the

finished surface, including pavement and

road level is to be non-frost susceptible

granular sub-base material Type 1.

6.2.8. Where it is a requirement for the

interior of the culvert to be dry, a drainage

system to reduce pore water pressure on

the rear face of the box culvert should be

provided. Otherwise this may be omitted.

6.2.9. Consideration must be given to the

weight of pre-cast concrete box culvert units

with respect to the size of crane required for

installation.

6.3. Pre-cast Concrete Circular Pipes

6.3.1. Circular reinforced concrete pipes

suitable for installation beneath highways are

to be strength class 120. Care must be

taken to ensure the appropriate crushing

loads provided in BS5911 are used in the

pipe design.

6.3.2. Loading on pipes can be determined

from “Simplified Tables of External Loads on Buried Pipelines” published by HMSO in

1986.

6.3.3. Guidance on bedding and surround

to pipes of different sizes (up to 900mm) and

strengths is given in Department of

Environment, Transport and Regions Advice

Note HA 40.

6.3.4. Circular concrete pipes greater than

900mm diameter and having depth of cover

greater than 0.6m but less than 10.0m must

be designed to Highways Agency Standard

BD82 ‘Design of Buried Rigid Pipes’.

6.4. Corrugated Steel Buried Structures

6.4.1. Corrugated steel structures shall not

be installed within 10 miles of the coast, or

wherever other climatic conditions may affect

their longevity.

6.4.2. The suitability of this type of culvert

depends on the depth from finished road

level to soffit, which must exceed 0.65 metres

or 1/5th span (whichever is greater). They

are not acceptable in locations where the pH

value of the groundwater is less than 4.5 or

exceeds 9.

6.4.3. They are usually designed by the

manufacturer and to the particular intensity of

highway loading appropriate to the class of

road. Design and installation of corrugated

structures must be in accordance with BD 12.

Highway loading as specified in BD 37 is to

be applied to all culverts over 0.6 metres

span/diameter.


6.4.4. The durability requirements are set

out in Chapter 8 of BD 12. In the absence of

appropriate soil/fill tests the Classification of

the Atmospheric Environment (Table 8) and

the Corrosivity Classification of the water or

effluent (Table 7) shall be taken as

“aggressive”.

6.4.5. The design must assume that no

maintenance repainting of the culvert will

be carried out and the inside face is therefore

designated “inaccessible”.

6.4.6. The minimum requirements for

excavation, bedding and surround of the

structures are given in Chapter 9 of BD 12.

Note that care must be exercised to ensure

an even distribution of load to either side of

the structure when backfilling.

6.4.7. In the absence of an appropriate

ground investigation report the trench width

shall not be less than three times the span or

diameter, the maximum value of Constrained

Soil Modulus used in the design shall be

20MN/m2 and the backfill shall be compacted

to not less than 85% of maximum dry density.

6.4.8. In cases where the pipe is being laid

beneath an existing carriageway and the sub-

grade material is cohesionless, the trench

width can be reduced to the minimum

required by Clause 9.5 of BD12, the design

value of Constrained Soil Modulus can be

taken as up to 33MN/mm2 and the backfill

shall be compacted to not less than 90% of

maximum dry density.

6.4.9. The finishes to the inner and outer

surfaces of the structure must be

galvanised/aluminised and provided with a

secondary protective coating by the

manufacturer prior to delivery.

6.4.10. For structures carrying water or

effluent invert protection shall be provided

using an appropriate method from Clause

8.16 of BD12/01 to protect against the effects

of abrasion/erosion.

6.5. Plastic Pipes

6.5.1. For circular culverts not exceeding

900mm diameter with a minimum cover of

1.5m on unclassified and ‘C’ class

carriageways, a plastic pipe of minimum ring

stiffness 6kN/m2 with BBÁ certification for use

as a highway drainage may be provided as a

permanent former for a structural concrete

bed and surround.

6.5.2. Care must be taken to prevent uplift

when pouring the concrete around the

pipe. This is usually achieved by strapping

down the pipe at regular intervals.

Justification will be required for the strength

capacity of the holding down straps.

6.5.3. The concrete surround must comply

with the minimum requirements for structural

concrete given in section 5 above, and must

extend a minimum of 300mm or span/2 each

side of the external face of the pipe and

500mm above the pipe.


7. Retaining Walls

7.1. Design and construction

requirements for backfilled retaining walls

are given in BD30.

7.2. Highway retaining structures may be

required to perform one of two basic

functions:-

(a) To retain ground which is

elevated above the highway

and not carrying highway

loading.

(b) To retain the highway above

lower adjacent areas (e.g. wing-

walls to culverts). In this case

the wall must be able to

withstand horizontal ground

pressures imposed by traffic

loading.

7.3. Any retaining wall within 3.65m of the

public highway with a height of greater than

1.35m will require the approval of

Lincolnshire County Council (under section

167 of Highways Act 1980)

7.4. Retaining walls will frequently be of

the ‘inverted T’ form and may be

constructed of either mass concrete,

reinforced concrete or brick. Other structural

forms such as crib walls or reinforced earth

may be acceptable if designed and

constructed in accordance with all relevant

standards.

7.5. Retaining walls must be designed to

provide adequate stability against

combinations of ground forces, any possible

traffic loading and vehicular impact.

7.6. The minimum factor of safety shown

below must be provided against both sliding

and overturning. If vehicular parapets are

provided, horizontal impact loads must be

considered in assessing overall stability.

Load 1 – Active earth pressures

Load 2 – Traffic surcharge

Load 3 – Vehicular impact

Load

Combination

FOS

Sliding

FoS

Overturning

1 2 2

1 + 2 2 2

1+ 2 +3 1.5 1.5

Appropriate active and passive earth

pressure coefficients should be used in the

stability analysis.

Careful consideration should be given to any

future excavation removing a restraining

effect, as a minimum the relieving effect of

any fill material within 0.5m vertically of the

final surface should be ignored.


7.12. Concrete retaining walls below

carriageway level on non-salted routes may

be designed for exposure class XC3,

otherwise exposure classes of XC3 / XD2

must be used. All concrete retaining walls

above carriageway level must be XD3.

7.13. Consideration should be given to the

appearance of concrete walls in urban and

residential environments, where the use of

brick cladding may be appropriate. Where

brick cladding is provided, this should be

attached to the supporting structure with

stainless steel fixings and any void filled with

the appropriate mortar.

7.7. In designing the integrity of structural

elements (i.e. bending and shear) the forces

due to earth pressures should be calculated

using an appropriate coefficient for earth

pressure at rest (see BS 8002 ‘Code of

Practice for Earth Retaining Structures’).

Where a retaining wall stem forms the

supporting member for a parapet it should be

designed for parapet loading in addition to

traffic loading and lateral earth pressures.

The structural analysis must consist of a limit

state design, considering both the ultimate

(ULS) and the serviceability (SLS). The

appropriate partial factors •fl, •f3, •m must be

applied for each condition.

7.8. The design must demonstrate

resistance to early thermal shrinkage of

immature concrete elements in accordance

with BA24.

7.9. Adjacent to the wall retained material

is to comprise suitable granular material to

Clause 610 of the Specification for a

minimum distance of 600mm from the wall

and is to be fully compacted in layers in

accordance with the Specification.

7.10. Where the length of wall exceeds 5

metres, consideration must be given to the

provision of joints to accommodate

shrinkage and small relative displacements

due to settlement.

7.11. Retaining structures should

incorporate suitable weep holes to relieve

pore water pressures.


8. Footbridges

8.1. The span of the footbridge required

will be dictated by the site geometry. The

provision of central supports (piers) shall be

assessed on the basis of safety, appearance

and economics; generally, a single span will

provide the optimum solution.

8.2. The design criteria for footbridges

are laid out in BD29. The enhanced criteria

in Clause 14.2 of BD29 will be adopted, so

that the footbridge may be used by disabled

people. The footbridge and its constituent

parts (deck, parapets, ramps, stairs and

supports) must be designed to carry the

loads given in Section 7 of BD37.

8.3. Structural steel is to be protected

with an appropriate paint system, see section

5.

8.4. “Very Durable” structural timber (as

stated in Building Research Report No. 296)

to BS5756 and BS5268 Part 2 Grade Stress

SC8 is required, from sustained sources.

Grade Stresses shown in Table 9 of BS5268

Part 2 must be employed for the design of

timber elements.

8.5. Timber is to be planed on all sides

with the exception of deck boards. Parapet

posts and handrails are to be “Pencil

Rounded” at the corners.

8.6. In “moderate use” situations deck

boards will have anti slip grooves machined

in the saw cut face the remaining three faces

being planed. In “heavy use” situations deck

boards will require an epoxy resin bauxite

chipping type system, or similar approved

system.

8.7. The presence of a cycleway or

equestrian route will require an appropriate

increase in the height of the parapets.

Consideration must be given to items being

deliberately thrown from the footbridge onto

the area below.

8.8. Any services are to be carried by the

footbridge in a manner which gives the

minimum possible visual impact.


9. Road Restraint Systems

9.1. The distance between the inside faces

of safety barriers or parapets must not be

less than 6.5 metres.

9.2. Where the appropriate risk

assessments require the provision of

vehicular containment, this may be provided

by either a parapet attached to the structure,

or a separate safety barrier. A safety barrier

does not provide protection for pedestrians,

and a further pedestrian barrier will be

required.

9.3. Safety barriers and vehicle parapets

are designated vehicle restraint systems

and the requirements for these items are

given in TD19.

9.4. The containment level and length of

need of a vehicle restraint system required

on the approach and departure to hazard are

given by the RRRAP computer programme,

subject to a minimum requirement specified

in TD19.

9.5. Vehicle restraint systems are specified

with a working width criteria. This working

width is measured from the traffic face of the

barrier and must be clear of other

obstructions, for a parapet the working width

may extend clear of the structure plinth.

9.6. The provision of crash cushions will

require the approval of Technical Services

Partnership, and may only be utilised in

exceptional circumstances.

9.7. Metal parapets will require mounting

on a suitable concrete plinth arrangement, for

vehicle parapets this will need to be a

minimum of 500mm width. Concrete parapet

plinths must be designed for exposure class

XD3. As an alternative to the requirements of

BD43 for impregnation, the plinth may be

constructed using strength class C40/50

concrete.

9.8. A parapet will require a safety barrier

to be installed at both ends, with an approved

transition between the systems. The

transition length is included in the length of

need, but generally will exceed the minimum

departure length.

9.9. Terminals shall be provided at each

end of a safety barrier. For roads with a

speed limit of 50mph or higher a class P4

energy impact absorbing terminal is required,

otherwise a class P1 terminal may be

provided.

9.10. Only vehicle restraint systems listed in

latest publication of the Highways Agency

‘HA Accepted EN1317 Compliant Road

Restraint Systems’ document will be

permitted.

9.11. Aluminium parapet systems shall not

be permitted in rural locations without prior

approval from Technical Services

Partnership.


9.12. Pedestrian parapets may be of steel

construction with vertical infill and must

comply with BS 7818. As an alternative a

vertical brick wall of not more than a single

brick (215mm) thickness may be provided

and should have an appropriate stone or

concrete coping.

9.13. Steel pedestrian parapets shall be

both galvanised and painted in an

appropriate colour in urban environments,

elsewhere these parapets may be galvanised

only.


10. ‘As Built’ Drawings & Maintenance Manual

10.1. A "Health and Safety File" in

accordance with The Construction (Design and Management) Regulations 2007 will be

required for all work affecting structures on

the public highway. Typically this would

include:-

(a) a brief description of the work

carried out, including key

structural principals and design

criteria;

(b) any residual hazards and

details of any hazardous

materials used;

(c) information regarding

demolition or dismantling of

the structure or installed

equipment;

(d) 'as-built' drawings

(e) general details (including

manufacturers and suppliers) of

materials used and methods

of construction;

(f) details of equipment and parts

which require maintenance,

including operating and

maintenance procedures; and

(g) details of the location and

nature of utilities and

services.

10.2. A separate health and safety file must

be prepared for each structure.

10.3. The adoption of any structure will

not be approved without the provision of

an accepted Health And Safety File.

10.4. On completion of a project or

structure, the client is required by the

Regulations to store the Health and Safety

File for the purposes of any future

maintenance or repair schemes. If the

client's interest in the structure is passed to

another body (e.g. if the Council adopts the

structure) the Health and Safety File shall

also be transferred.

10.5. If the structure is non-adoptable, then

the County Council requires a copy of the as-

built drawings of all highway structures for its

records.


Note: These lists are not exhaustive and do

not contribute a Technical Approval schedule

The Design Manual for Roads and Bridges

(including BA, BD, HA, HD, TA, TD, IAN) and

Manual Of Contract Documents for Highway

Works (including SHW, NfGSHW, HCD) are

available at www.standardsforhighways.co.uk

For technical approvals

BD2 Technical Approval of Highway

Structures

For general design and loadings

BD 15 Use of BS 5400 Part 1: 1988.

BD 29 Design criteria for footbridges

BD 30 Backfilled retaining walls and bridge

abutments

BD 31 Buried concrete box type structures

BD 37 Loads for Highway Bridges

BD74 Foundations

BD82 Design of Buried Rigid Pipes

BS 5400 pt.2 Specification for loads

BS 8002 CP for Earth Retaining

Structures

BS 8004 Foundations

Simplified Tables of External Loads on

Buried Pipelines

Appendix A – Key Documents (Codes Of Practice And Design Documents)

For material specific properties

BD 12 Corrugated steel buried structures

BD 13 Use of BS 5400 Part 3: 1982

BD 24 Use of BS 5400 Part 4: 1990.

BD 28 Early Thermal Cracking of Concrete

BD 47 Waterproofing and surfacing of

…bridge decks

BS 5268 Structural Use of Timber

BS 5911 Specification for … reinforced

concrete pipes ….

BS 5400 pt.3 CP for design of steel bridges

BS 5400 pt.4 CP for design of concrete

bridges

BS 5628 Un-reinforced masonry

BS8500 Concrete … method of

specifying ….

BS7818 Pedestrian restraint systems

… in metal

For highway design and safety barriers

TD27 Cross-sections and Headroom

TD19 Road Restraint Systems

TD9 Highway Link Design

BS EN 1317 ….. Safety Barriers …..


Other useful documents

Good Bridge Detailing Guide

BS8666 Scheduling ….. Reinforcement

HA Accepted EN1317 Compliant Road

Restraint Systems

(available from www.highways.gov.uk)

Road Restraint Risk Assessment Process

(available from www.highways.gov.uk. Note:

The latest version must be downloaded each

time before use)

CSS - Commuted Sums for Maintaining

Infrastructure Assets Guidance Document

(available from www.cssnet.org.uk)

Lincolnshire County Council Documents

(Available on request)

HAT34 Design Standards And Departures

For Highway Schemes

(Improvements, Maintenance And

Developments)

HAT40 Commuted sums for Maintenance

HAT51 Provision Of Vehicle Restraint

Systems (& PVRSAS)

HAT63 Safety Audits Policy and Guidance

DPD33 Traffic Management Act 2004 –

Registration of Works and Road

Space Booking System

Standard Drawings and Typical Details

(available from www.lincolnshire.gov.uk)

The Manual Of Contract Documents for

Highway Works

Specification for Highway Works

Notes for Guidance on the Specification for

Highway Works

Highway Construction Details


All highway structures will require technical

approval in accordance with BD2. Each

structure type is allocated a category (0, 1, 2

or 3) which defines the technical approval

requirements for the structure. Technical

Services Partnership will act as TAA.

BD2 gives guidance on selecting a category

appropriate for the type of structure

proposed. The category of a structure should

be agreed with Technical Services

Partnership prior to the commencement of

detailed design. The category of the structure

may change as the design evolves.

A structure that does not conform to

published standards is either a category 2

or 3, this includes requirements for safety

barriers and parapet provision. Note: use of

the PVRSAS for situations beyond the scope

of the RRRAP does not contribute a

Departure from Standards.

The Approval In Principal process may be the

appropriate method for endorsing

Departures From Standards, otherwise a

separate Departure from Standard

submission will be required.

The following design certification will be

required, and must be submitted with full

design documentation as described below:

For all structures a Design Certificate will be

required for endorsement by the TAA.

For structures categories 1, 2 or 3 an

Approval In Principal will be required,

including a Technical Approval Schedule.

This shall be completed and submitted to the

TAA together with all necessary drawings

and other documents for agreement or

amendment.

For category 2 and 3 structures a Check

Certificate will also be necessary for TAA

endorsement. Category 3 structures require

this check to be completed by an

independent organisation.

The documentation accompanying the

Design and Check Certificates shall

comprise a full set of construction drawings

and full structural calculations written out in

sufficient detail as to be easily followed by a

competent engineer and including:

• Statements of principles employed in

analysis

• Clear references to clauses of

relevant design standards

• Diagrams and sketches as required

for clarity

• Input data for any computer program

utilised

• Computer output marked to indicate

results used in the calculations and

design.

Appendix B - Technical Approval Requirements


Maximum deviation from line on LINE TOLERANCE

Given

Line 10m chord 20m chord 3m straight

Maximum

between

units

Other

requirements

Walls, vertical

or horizontal

± 7

mm 7 mm 7 mm 5 mm

Soffit edges ± 7

mm 10 mm 7 mm 5 mm

Copings ± 10

mm 5 mm 3 mm

± 7 mm over

complete length

being over 30m

Parapet

plinths

± 10

mm 5 mm 3 mm

Footways ± 15

mm 10 mm Width ± 7 mm

Channels ± 15

mm 10mm Width ± 5 mm

Appendix C – Construction Tolerances

Maximum acceptable construction tolerances (Y1) are specified as below:

10m or 20m chord

Y2

Specified line or level

Y1

Actual construction

Y1 – Max. deviation from line as constructed Y2 – Max. tolerance in line or level

Diagram of deviation / tolerance relationship


Max. deviation from line LEVEL TOLERANCE

Given

Levels 10m chord 3m straight

Maximum

between

units

Other

requirements

Abutments, pier

tops, crossheads

–normal to span

± 7 mm 5 mm

Abutments, pier

tops, crossheads -

parallel to span

± 7 mm ± 3 mm

across width

Beam soffit ± 7 mm 5 mm

Deck concrete ± 10 mm 10 mm Ridge height

max. ± 4 mm

Copings ± 10 mm 5 mm 2 mm

Parapet plinths ± 10 mm 5 mm

Channels,

footways ± 10 mm 7 mm



HIGHWAYS ALLIANCE


Street Lighting Contents

General Purpose (NB Only this section included in CPO information as remainder not relied

on for design by internal teams)

Consultancy

Policy

Scope

Project Management

District Network Operators (DNO)

Requirements

Street Lighting Standards

Disconnection of Existing Lighting

Setting Out

Adoption

Specification Model Specification

Steel Columns

Hinged Columns

Lanterns

Lamps and Control Gear

Photocells

Manufacturers

Typical Details

Further Information

Appendices Sample Development Road Specification

Lanterns

Approved Equipment Manufacturers

Typical Details

Technical Services Partnership Street Lighting Design Guide General Purpose The purpose of this Guide is to provide guidance for developers and consultants who are engaged in the design of street lighting and associated equipment intended for existing or proposed highway. This document is a live publication and is only current at the time of use. The user should not print off copies of any of the guidance notes and continue to refer to them, but rather should access the information as new from the web based master copy.


Traffic Signals Contents

HAT 52 Traffic Signals Design Guide




HIGHWAYS ALLIANCE


Signs & Lines Contents

HAT 31 Road Markings HAT 32 Traffic Signs HAT 50 Tourism Signing Policy Passively Safe Assemblies

Risk Assessment





../../DOCUMENTS/Passively%20safe-risk%20assessment.xls


Author: R D May

Safety Audits

Scope The guide deals with the commission of Safety Audits. It does not deal with Exception Reports (D109.01) or Departures from Standards (D110.01). Standards Subject to the contents of HAT 34 the following standards may be applicable. (NOTE: Documents not contained in HAT 34, such as new standards, may be of relevance to some schemes.) HAT 62 Safety Audit Policy and Guidelines link to document Application The guide applies to all Schemes designed within the Highways Alliance. It also applies to any scheme designed by outside bodies for checking by TSP. Notes/Guidance Designers will need to take into account the following: -

All schemes designed in TSP will be subject to Safety Audit. There are three stages to Safety Audits

Stage 1 – Preliminary Stage 1 audit should be undertaken when the design has evolved sufficiently to enable progression to detailed design, but before detailed design has been undertaken. This Stage is not necessary on minor schemes.

Stage 2 – Pre Contract Stage 2 audit should be undertaken prior to tender, or in the case of a scheme being undertaken through the term maintenance contract prior to the issue of the works order.

Stage 3 – Post Construction Stage 3 audit shall be undertaken upon completion of the works on site. Completion shall mean with all street furniture, signs and lines in place.

All audits shall be undertaken by the Accident and Investigation section of the Lincolnshire Road Safety Partnership.




Author: R D May

Audits typically take around four weeks from the placing of the instruction with LRSP.

A detailed schedule of the information being supplied, together with a description of the works to be audited should be sent with the instruction to AIP.

The designers response to safety audits is dealt with in D109.01 Exception Reports.

Where practicable the design shall be changed in line with the recommendations of the Safety Audit.

Safety Audits do not relieve the designer of his/hers responsibilities. Designers must ensure that the design is as safe as possible within the constraints of the project.

Where the Designer has concerns over the recommendations contained in a safety audit they must discuss them initially with an independent Principal Engineer and then, if required, the Safety Auditor.

REMEMBER the Safety Audit is a public document and may be used in Legal Proceedings should things go wrong.


Author: R D May

Safety Audit, Exception Reports

Scope The guide deals with the production and approval of Exception Reports arising from Safety Audits. It does not deal with Safety Audits (D108.01) or Departures from Standards (D110.01). Standards Subject to the contents of HAT 34 the following standards may be applicable. (NOTE: Documents not contained in HAT 34, such as new standards, may be of relevance to some schemes.) HAT 62 Safety Audit Policy and Guidance link to document Application The guide applies to all Schemes designed within the Highways Alliance, including S278 and estate roads. Notes/Guidance Exception reports arise from the recommendations set out in a safety audit report. They are not Departures from standard. Where the matter cannot be dealt with through a design change, or alterations to the works at a stage 3 audit, the reasons and the approval of those reasons need to recorded in an Exception Report. A copy of the form to be used can be found at HAT62 Appendix C. It may be that it is not possible to meet the recommendations set out in the Safety Audit, but some measure of mitigation can be implemented. If this is the case these measures should be recorded in the report. Where the works are commissioned by the Divisional office, or is a S278 or S38 scheme then the Head of Highways for that division will need to approve the Exception Report. It is usual to discuss the need for the report and it’s recommendations prior to submission to the relevant Head of Highways. Where the work is commissioned by the capital client, the Head of Highways East will need to approve the report. All Exception Reports will be reviewed by a Principal Engineer prior to submission.





Author: R D May

Legitimate factors that can be taken into account when applying for an exception include practicality, cost and availability of land amongst others. It is also appropriate for the designer to disagree with the recommendation if he/she feels that it will create an additional hazard or if the designer does not believe that it will improve safety. If this is the case then the designer will need to record this in a risk assessment. It is also appropriate to apply for an exception if the recommendation addresses matters outside the scope of the works e.g. poor maintenance of existing carriageway. REMEMBER the Exception Report is a public document and may be used in Legal Proceedings should things go wrong.


Author: R D May

Departure from Standard Scope The guide deals with the production of and application for Departure from Standard. It does not deal with Safety Audits or Exception Reports. Standards Subject to the contents of HAT 34 the following standards may be applicable. (NOTE: Documents not contained in HAT 34, such as new standards, may be of relevance to some schemes.)

All design guides and associated materials. Application The guide applies to all Schemes designed within the Highways Alliance. The guide also applies to any schemes designed outside of Technical Services Partnership including those for checking by TSP. Notes/Guidance A Departure from Standard arises when it is not possible to meet the minimum requirements set out in the relevant design standard. The need for a departure shall be determined during the development of the design. TD9/93 gives examples of the factors that may be considered when applying for a Departure from standard. In particular reference to paragraphs 0.12 to 0.16 inclusive and paragraphs 1.15 to 1.27 inclusive gives appropriate guidance. Prior to applying for a Departure from Standards the designer shall discuss the options with a Principal Engineer who will decide whether to pursue the application. The reasons and the approval of those reasons need to be recorded in a Departure from Standard. . A copy of the form to be used can be found at HAT 34 – Appendix D. The relevant Head of Service is responsible for the approval of Departures from Standard. All Departures from Standard will be reviewed by a Principal Engineer prior to submission. The application will need to set out the following: -

The standard which cannot be met.

Alternatives considered with reasons for rejection.



Author: R D May

The recommended solution, including the standard that can be achieved, together

with a supporting risk assessment shall be included.

Where the client is the Head of Highways or a member of their staff and the design brief includes for a substandard design, then their instruction will be accepted as an approval to Depart from Standard except where the client in internal to Technical Services. As such a formal departure from standard signed by the relevant Head of Service will not be required. This is due to the function carried out by the Divisional Head of Highways and their staff ie: management of the local highway network and the improvement of existing facilities. However the lead design engineer should ensure that the client is aware that what they are requesting does not meet the normal standards. Safety audit must be carried out in this situation.


Author: R D May

Traffic Regulation Orders

Scope The guide deals with the need and implementation of Traffic Regulation Orders. It does not deal with Side Road Orders or Compulsory Purchase Orders. Standards The following standards will apply: - Application The guide covers all schemes that require an order to regulate traffic. Notes/Guidance The Highways Act defines those aspects of signing/regulation that require enforcement. Permanent Orders, examples include: -

Parking restrictions (yellow lines)

One way restrictions

Speed limits

Signalised crossings (not traffic signals)

Bus stops regulated by bus stop carriageway markings

Box junctions

Pedestrian Crossings

Temporary Orders, examples include:-

Speed Limits in Road Works

Temporary Diversion of Traffic/Temporary Road Closures

The list is not comprehensive so the designer shall establish the need for any orders during the evolution of the design and in discussion with the client/ Area Highways Office. Traffic Regulation Orders are legally enforceable orders that regulate the use of the Highway. The Order only becomes enforceable once it has been through a defined Statutory Process. Divisional staff will usually undertake this process. For schemes that


Author: R D May

do not originate in the divisions it is vital that Divisional Highways Manager support for the Order is obtained. This Process includes: -

Drafting of the Order and the Statement of Reasons.

Advertising/Publishing the Draft Order.

Consultation.

Application to Planning and Regulation Committee.

Implementation of the Order. Obtaining a permanent Traffic Regulation Order can take in excess of 9 months. Even though the Order may be vital to the scheme, approval by committee cannot be guaranteed.

Considerations in Design

NRSWA

Depth Proximity Detection / Measures Prevention / Alternatives

Environment

Commercial / Industrial Local Amenities Residential /Developments Elderly / Disabled Schoolchildren Pedestrians / Cyclists Town Centre

Traffic

Emergency Access Traffic Flows Traffic Speed HGV / Deliveries Traffic Management Road Widths / Safety Zones Road Closures Diversions Weight Limits Access

Construction

Structures Depths of Excavations Confined Spaces Falls from Height Contaminated Land Ground Investigation Proximity of works / Hazards Temporary Surfaces Demolition Asbestos / Lead Watercourses Adjacent Buildings Plant and Equipment Materials Noise and Dust Manual Handling Maintenance of Works

Audit Trail

Risk Reduction Recorded Design Decisions Recorded Risk Assessment Health and Safety Plan Reviews

Guidance notes on the design, construction, approval and ...

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