Information Session - “Traffic Engineering”

Date: Tuesday, 12 January 2010

Time: 3:00 pm

Location: ENG-LG06

Mr. Richardson’s talk will first give a very brief overview of the work done by his company in the

areas of surveying, mapping, building engineering, municipal design, landscape architecture,

planning, environmental, water resources, and project management. The talk will then focus

exclusively on traffic engineering and will cover everything from signal phasing and timing,

control modes, traffic hardware, intersection design, medians, pavement markings, signal co-

ordination, intersection capacity analysis, saturation flow and interesting trivia on traffic

engineering-related information.

Mr. Dave Richardson, P.Eng., PTOE, Senior Project Manager, Transportation Planning, is a

Partner of MMM Group Limited. Dave joined MMM in 1990 after 17 years with the Transportation

Department of Metropolitan Toronto. While at Metro, he was responsible for the management of

the Traffic Control Centre which monitors, co-ordinates and continuously optimizes over 2,000

traffic control signals. Dave is the co-author of the 1984, 1995 and 2008 editions of the

Canadian Capacity Guide for Signalized Intersections, and has done extensive research into

traffic control signal safety and operations. He has written numerous papers and has lectured

extensively on this subject. He is the firm’s prime consultant on all matters relating to traffic

signal safety, design, installation, phasing, timing, co-ordination and analysis. While at Metro

Toronto, he also managed the Research and Investigation Division which was responsible for

analyzing more than 50,000 collisions which occurred annually on City streets and Metro roads.

Over the course of his 35-year career, he has undertaken a broad range of planning, design,

value engineering, pedestrian, transit, bicycle and safety related projects for both public and

private sector clients both locally and internationally.

Contact

For further information on this event or on RITE, contact us:

� President: Saad Syed � Vice-President: Bernard James

Phone: (647) 302-1259 Phone: (416) 876-1546

Email: s6syed@ryerson.ca Email: bjames@ryerson.ca

� Faculty Advisor: Dr. Bhagwant Persaud

Phone: (416) 979-5000 ext. 6464

Email: bpersaud@ryerson.ca

� Website: www.civil.ryerson.ca/citesc

Traffic Engineering

Dave Richardson, P.Eng., PTOE

January 12, 2010

MMM Group Limited

Founded in 1952

Over 1,750 staff

Employee owned and operated, with one private equity investor

Offices across Canada, in U.S. and internationally

Integrated service delivery

Active in public, private and P3 sectors

Recognized Canadian leaders in alternative delivery, program/project management (Canadian Consulting Engineer PM award winner 2003, 2004, 2005, 2006)

Principal Market Sectors

Communities

Transportation

Buildings

Infrastructure

Cornell Community,

Markham, ON

Sea-to-Sky Highway, BC

William Osler Hospital, Brampton,

ON

York-Peel Feedermain,

York Region, ON

Principal Fields of Activity

Program/project management Transportation planning and engineering Building/structural engineering Mechanical/electrical engineering Municipal land development Environmental planning/water resources Urban/economic planning and landscape

architecture Geomatics

Planning

Fletcher’s Creek Secondary Plan, Brampton

CornellDevelopmentin Markham

Landscape Architecture

York University Ice Gardens

Geomatics

MMM led design team JV and project manager

Environmental/Water Resources

Restoration of Levi Creek

Wascana Creek Water Control Study

First…a Few Definitions

What is this thing?

– Traffic control signals (TCS)

– Traffic signals

– Signals

What it’s not:

– Stop lights

– Traffic lights

– Lights

Definitions cont’d

What is this??

– Display

– Indication

– Aspect

What it’s not…

– A phase

Definitions cont’d

How big is it??

– 200 mm (8”)

What colour is the lens??

– Blue

Basics of Signal Phasing

What is a Phase??

– A phase is a sequence of displays that govern one or more simultaneous movements at an intersection.

Now for some trivia…

Where and when was the world’s first traffic control signal installed?– George & Bridge Streets, London, England, 1868

Where and when were the first traffic signals installed in Canada?– King and James Streets, Hamilton, ON, July 1925

Where and when were the first traffic signals installed in Toronto?– Bloor & Yonge Streets, August 1925

How many signalized intersections are in the City of Toronto?– 2,117

Hardware definitions

Mast arm

Signal head

Hardware definitions cont’d

Pole configuration

Hardware definitions cont’d

Pole bases

Hardware definitions cont’d

Pushbuttons

Hardware definitions cont’d

Detector loops

Poor Design

Poor Design cont’d

Curb cuts at signalized intersections

A detector loop for??

Poor Design cont’d

Medians

Asymmetrical bullnose

Symmetrical bullnose

Pavement markings

Stop bars

Crosswalk lines

Centre lines

Lane lines

Pavement markings cont’d

Bike lanes

Bus lanes

HOV lanes

Edge lines

Signal Phasing

Rule #1…Simplicity!

Rule #2…Minimize the # of phases

Rule #3…Minimize the cycle length

Question: What governs minimum cycle length?

Signal Phasing and Timing

Typically between 50 and 120 seconds

– Up to 140 seconds in extreme cases; 144 seconds in SCOOT

Phase structure

– Two phase

– Multiphase

Timing

– Green

– Effective green

– Intergreen

– Lost time

– Vehicle extensions

Control Mode

Fixed time

Semi-actuated

Fully actuated

Control Mode cont’d

Detector loops

– Presence

– Passage

Other detectors

– Infrared

– Ultrasonic

– Microwave (Radar)

– Radio (Spread Spectrum)

– Video

Signal Coordination

2 signals 60 second cycle 50/50 split 30 seconds travel time between signals

t = 0; t = 60t = 30

Signal Coordination cont’d

3 signals

60 second cycle

50/50 split

15 seconds travel time between signals

t = 0; t = 60t = 30

Wal-Mart

t = 15; t=45

What were they thinking??

What were they thinking??

Trivia!

Where in Canada can you legally drive the fastest?

– In Alberta, the posted speed limit on highways is 110 km/h

Saturation Flow

What is saturation flow?

The departure rate from a queue during the green interval measured at the stop line

“Under prevailing roadway and traffic conditions”

Saturation Flow cont’d

Saturation Flow cont’d

Question…

Do you think it’s a good idea to raise the speed limit on 400-series highways in Ontario?

Saturation Flow cont’d

Typical Saturation Flow Values

Through Movement

Approach

Environment Victoria Vancouver Calgary Edmonton Hamilton

Greater

Toronto Ottawa

Low Activity

(suburban)1800 1850 1850 1750 1830 1870 to 1950 1815

High Activity

(downtown)1700 1750 1550 1650 1680 to 1750 1600

Saturation Flow cont’d

Relation between the CCG and HCM Saturation Flow Values

CCG 3rd Edition (2008) includes a regression relationship

between saturation flows

SHCM = 1.05 SCCG

HCM 2000 has modified its description of the delay formula and

the saturation flow measurement techniques. The new

definition for HCM Saturation Flow is closer to the CCG

Saturation Flow definition

There is a need for updating the relationship between the two

saturation flows based on simultaneous saturation flow surveys

Saturation Flow Adjustment Factors

Geometric Conditions

Traffic Conditions

Control Conditions

Saturation Flow Adjustment Factors cont’d

Geometric Conditions

– Lane width– Grade– Turning radius– Queuing and discharge space

Saturation Flow Adjustment Factors cont’d

Traffic Conditions

– Transit stops

– Parking

– Pedestrians

Saturation Flow Adjustment Factors cont’d

Control Conditions

– Duration of green interval– Protected left turns– Permissive left turns– Permissive left turns with pedestrians– Right turns with pedestrians– Various shared lane combinations

Saturation Flow Adjustment Factors cont’d

C = S(g/c)

Question…

4-legged intersection

4 vehicles approaching – 1 from each direction– Police

– Fire

– EMS

– Canada Post Signals stuck in all red

Who has the right-of-way?

Intersection Capacity Analysis

Intersection Level of Service

Should a letter grade be assigned to qualitatively assess the operation of an intersection?

Delay based or v/c based?

Intersection Capacity Analysis cont’d

“Richardson’s Laws of Intersection Capacity”

No two intersections are created equal

Intersection capacity is only an estimate

There are only 60 seconds in a minute!

Intersection Capacity Analysis cont’d

No Two Intersections Are Created Equal

Geometry

Signal Phasing

Signal Timing

Lane Distribution

Transit Stops

Intersection Capacity Analysis cont’d

No Two Intersections Are Created Equal

Environment

Traffic Composition

Traffic Volume

Pedestrian Activity

Intersection Capacity Analysis cont’d

Intersection Capacity is Only an Estimate

Many techniques

No absolutes

Based on “expected” or “predicted” traffic (driver) behaviour

Traffic and pedestrian flows change dynamically

Intersection Capacity Analysis cont’d

There Are Only 60 Seconds in a Minute!

What are the trade-offs?

What is the objective function?– Minimize delay

– Minimize queuing

– Balance v/c’s

– Minimize stops

– Maximize “safety”

Intersection Capacity Analysis cont’d

Left Turn Capacity

4 regimes of left turn capacity

1) On priority movement

2) During saturated opposing thru movement

3) “Gaps” in opposing thru movement

4) During the intergreen

Question…

What is the longest street in the world?

Yonge Street at approximately 1,900 km

Question…

Where does the QEW get its name from? What year did it open?

The “Queen Mom”, in 1939

Question…

What was the maximum speed limit on Ontario’s roadways in 1903?

15 mph or ~24 km/h(obviously the cars weren’t this flashy!)

Question…

What were two of the first ways police used to stop speeding motorists?

• Police would attach a taut chain to two sturdy trees on either side of the road to stop motorists (rather abruptly!)

• Police would throw a plank studded with nails in the path of speeding motorists

Question…

What year were driver’s licenses first introduced? Which drivers were targeted by the legislation?

Starting in 1909, chauffeurs were the only drivers required to acquire a driver’s license because they didn’t own vehicles and were thus deemed to be negligent. It was merely a formality since no test was ever administered.

Questions…?