WelcomeTo

Intersection Design

Presented at:Bentley 2009 Roads and Bridge ConferenceCharlotte, North Carolina

Presented by:Dirk Karasek

The Envision Group, Inc.

www.EnvisionCAD.com

Goal

A Comprehensive Intersection Model

Methods

Options• Secondary Alignments

Methods

Options• Secondary Alignments• Multiple Adjoining Corridors

Methods

Options• Secondary Alignments• Multiple Adjoining Corridors• Overlapping/Clipping Corridors

Radius Returns All three options require radius return alignments

The multicenter curvecommand createshorizontal alignments

Radius Returns All three options require radius return alignments

It also can create vertical alignments

Secondary Alignment Method

Quick overview

• Templates are run perpendicular to the reference lines

Secondary Alignment Method

Quick overview

• Templates are run perpendicular to the reference lines• Only 1 template is required for each roadway

Secondary Alignment Method

Quick overview

• Templates are run perpendicular to the reference lines• Only 1 template is required for each roadway• All template origins are tied to reference line alignments

Secondary Alignment Method

Quick overview

• Templates are run perpendicular to the reference lines• Only 1 template is required for each roadway• All template origins are tied to reference line alignments• Radius returns are defined as ‘secondary’ alignments

Secondary Alignment Method

Quick overview

• Templates are run perpendicular to the reference lines• Only 1 template is required for each roadway• All template origins are tied to reference line alignments• Radius returns are defined as ‘secondary’ alignments• The template ‘bends’ at the secondary alignment

Secondary Alignment Method

Quick overview

• Templates are run perpendicular to the reference lines• Only 1 template is required for each roadway• All template origins are tied to reference line alignments• Radius returns are defined as ‘secondary’ alignments• The template ‘bends’ at the secondary alignment• The radius return alignment is a horizontal control only

Secondary Alignment MethodTemplate ‘bends’ at secondary alignment

Orig

in

Secondary Alignment MethodTemplate ‘bends’ at secondary alignment

Secondary Alignment Method

Triangulation results

Secondary Alignment Method

Suitable when matching minor road to edge of major road

Multiple Adjoining/Corridors Quick overview

• All template origins are tied to horiz/vert alignments

Multiple Adjoining/Corridors Quick overview

• All template origins are tied to horiz/vert alignments • Templates are run perpendicular to the reference lines

Multiple Adjoining/Corridors Quick overview

• All template origins are tied to horiz/vert alignments • Templates are run perpendicular to the reference lines• Templates are also run radial to the radius returns

Multiple Adjoining/Corridors Quick overview

• All template origins are tied to horiz/vert alignments • Templates are run perpendicular to the reference lines• Templates are also run radial to the radius returns• A single template is used for the radius returns

Multiple Adjoining/Corridors Quick overview

• All template origins are tied to horiz/vert alignments • Templates are run perpendicular to the reference lines• Templates are also run radial to the radius returns• A single template is used for the radius returns• Vertical alignments along radius returns can be edited to

control the edge of pavement or curb flowlines

Multiple Adjoining/Corridors Quick overview

• All template origins are tied to horiz/vert alignments • Templates are run perpendicular to the reference lines• Templates are also run radial to the radius returns• A single template is used for the radius returns• Vertical alignments along radius returns can be edited to

control the edge of pavement or curb flowlines• Corridors can overlap and will automatically ‘clip’

underlying corridors.

Multiple Adjoining/Corridors

Multiple Adjoining/Corridors

Cons & Pros• Mainline and side road each require 3 or 4 unique

templates

Multiple Adjoining/Corridors

Cons & Pros• Mainline and side road each require 3 or 4 unique

templates• ~ 13 corridors required

Multiple Adjoining/Corridors

Cons & Pros• Mainline and side road each require 3 or 4 unique

templates• ~ 13 corridors required• User must determine template start/stop limits

Multiple Adjoining/Corridors

Cons & Pros• Mainline and side road each require 3 or 4 unique

templates• ~ 13 corridors required• User must determine template start/stop limits• Corridor definitions can be complex

Multiple Adjoining/Corridors

Cons & Pros• Mainline and side road each require 3 or 4 unique

templates• ~ 13 corridors required• User must determine template start/stop limits• Corridor definitions can be complex• Changes in design require revisiting many

template/station entries

Multiple Adjoining/Corridors

Cons & Pros• Mainline and side road each require 3 or 4 unique

templates• ~ 13 corridors required• User must determine template start/stop limits• Corridor definitions can be complex• Changes in design require revisiting many

template/station entries• Finished model is complete with surfaces and

components

Overlapping/Clipping Corridors

Overlapping/Clipping Corridors

Corridors• Mainline corridor contains a single template entry

Overlapping/Clipping Corridors

Corridors• Mainline corridor contains a single template entry• Sideroad corridor contains a single template entry

Overlapping/Clipping Corridors

Corridors• Mainline corridor contains a single template entry• Sideroad corridor contains a single template entry• Each quadrant contains a single template entry

Overlapping/Clipping Corridors

Corridors• Mainline corridor contains a single template entry• Sideroad corridor contains a single template entry• Each quadrant contains a single template entry

Sequence of events

1. The mainline ‘clips’ the sideroad model

Overlapping/Clipping Corridors

Corridors• Mainline corridor contains a single template entry• Sideroad corridor contains a single template entry• Each quadrant contains a single template entry

Sequence of events

1. The mainline ‘clips’ the sideroad model

2. The quadrants ‘clip’ both the mainline and sideroad models

Overlapping/Clipping Corridors

Corridors• Mainline corridor contains a single template entry• Sideroad corridor contains a single template entry• Each quadrant contains a single template entry

Sequence of events1. The mainline ‘clips’ the sideroad model2. The quadrants ‘clip’ both the mainline and sideroad

models3. A single composite surface is created

Clipping CorridorsTemplate along radius returns

Orig

inO

rigin

Point controls used to target mainline or sideroad corridors

Variableslope & length

Clipping CorridorsTemplates placed perpendicular or radial

Crownline

Targeted

Quadrant corridor

Edge of thru-la

ne

Targeted

Normal end-condition applied

Overlapping/Clipping Corridors Contours

Overlapping/Clipping Corridors

Suitable when matching minor road to edge of major road or crown to crown

Overlapping/Clipping Corridors

Pros & Cons• Mainline and side road each require only 1 template

Overlapping/Clipping Corridors

Pros & Cons• Mainline and side road each require only 1 template• 1 template for all quadrants

Overlapping/Clipping Corridors

Pros & Cons• Mainline and side road each require only 1 template• 1 template for all quadrants• Total of 6 corridors required

Overlapping/Clipping Corridors

Pros & Cons• Mainline and side road each require only 1 template• 1 template for all quadrants• Total of 6 corridors required• Easy to define corridors

Overlapping/Clipping Corridors

Pros & Cons• Mainline and side road each require only 1 template• 1 template for all quadrants• Total of 6 corridors required• Easy to define corridors• Creates composite surfaces DTM(s)

Overlapping/Clipping Corridors

Pros & Cons• Mainline and side road each require only 1 template• 1 template for all quadrants• Total of 6 corridors required• Easy to define corridors• Creates composite surfaces DTM(s)

Overlapping/Clipping Corridors

Pros & Cons• Mainline and side road each require only 1 template• 1 template for all quadrants• Total of 6 corridors required• Easy to define corridors• Creates composite surfaces DTM(s)• Changes in design may require recreation of radius

returns

Demo/Questions?

Thank You!

Intersection Design

Presented at:Bentley 2009 Roads and Bridge ConferenceCharlotte, North Carolina

Presented by:Dirk Karasek

The Envision Group, Inc.

www.EnvisionCAD.com