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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: [email protected] Email: [email protected]
� Faculty Advisor: Dr. Bhagwant Persaud
Phone: (416) 979-5000 ext. 6464
Email: [email protected]
� Website: www.civil.ryerson.ca/citesc
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
First…a Few Definitions
What is this thing?
– Traffic control signals (TCS)
– Traffic signals
– Signals
What it’s not:
– Stop lights
– Traffic lights
– Lights
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
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 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
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
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 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
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 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.