Transcript Slide 1
TRAFFIC SIGNAL
MANAGEMENT
PURPOSE
Purpose: Foster understanding
through development of educational
outreach materials
Illustrate benefits and basic techniques
Share information on new technologies
Highlight need for multi-municipal
cooperation
Target Audience:
Municipal Officials, Planning Commission
Members, Municipal Staff Members
WHAT IS TRAFFIC SIGNAL
MANAGEMENT?
The use of current tools, techniques
and equipment to manage streets and
signal systems more efficiently and in a
cost-effective manner in order to
improve safety, economic vitality and
quality of life.
WHAT IS TRAFFIC SIGNAL
MANAGEMENT?
The #1 investment we can make for
immediate positive impact.
Cost-effective way to improve traffic
flow.
Maximizes the benefits of the existing
infrastructure.
WHY TRAFFIC SIGNAL
MANAGEMENT?
2/3 of all miles driven are on signalized
roads
Over 300,000 signals in U.S.
75% of the signals could easily be upgraded
Congestion affects everyone’s mobility
Adding capacity
Expensive
Long implementation timeframe
Potentially controversial
Environmental and social impacts
WHY TRAFFIC SIGNAL
MANAGEMENT?
Properly designed, operated and
maintained traffic signal systems yield
significant benefits:
Less Congestion
Improved Fuel Consumption
Vehicle Emissions Reduced
Improved Air Quality
WHY TRAFFIC SIGNAL
MANAGEMENT?
Cost effective: cost ratios of 40:1
Low-cost alternative to physical
reconstruction
Arterial management
Saves time for commercial vehicles,
emergency vehicles, buses and the
public
Reduces aggressive driving behavior, red
light running
WHY TRAFFIC SIGNAL
MANAGEMENT?
Postpone or eliminate need for
additional capacity
Safety – reduce accidents by
providing smoother traffic flow with
fewer stops
Maintenance and training streamlined
Improved pedestrian flow, side-street
movements
Municipal cost and energy savings
HOW CAN BENEFITS
BE ACHIEVED?
STRATEGIES
Standardization of equipment
Remove unwarranted signals
Install and maintain equipment
properly
Traffic signal retiming
Implement additional signal plans based
on time of day/day of week
Turn lanes and minor intersection
improvements
STRATEGIES
Traffic Signal Equipment
Enhancements:
Isolated or independent signals
Arterial Interconnected Signals
Time based coordination
Closed Loop Systems
Centrally Interconnected & Controlled
Systems
Personal computer (PC) based
Traffic Operations Centers
Detection & Actuation
Strategies
Fixed Time Operations
Semi Actuated Operations
High traffic and pedestrian volume areas,
Not flexible for changing traffic patterns
Central Business Districts hours
Applicable to corridors
No detectors or actuation on main streets
Fully Actuated Operations
Most flexible
Best for isolated signals
GOALS
Centralized coordination of signals
Coordinate signal operations over
jurisdictional boundaries
Integrate traffic flow over larger areas
Corridor Administrator to set up and
implement
Municipal Training
Dedicated funding stream
Administrative hierarchy
MULTI - MUNICIPAL COOPERATION
Procurement Methods:
Department of General Services (DGS)
COSTAR program
Purchase equipment as public procurement unit =
economies of scale lower costs
Cost Sharing concept allows municipalities
with smaller budgets to benefit too
MULTI - MUNICIPAL COOPERATION
Equipment better maintained
Reduced liability
Maintenance streamlined with standardization
Funding for larger projects
Municipality retains basic timing parameters
Costly reconstruction postponed by utilizing
existing facilities more efficiently
Repairs made more quickly
Traffic Signal System
Improvement Program
Traffic Signal Retiming
Signal Maintenance Strategies
Utilize New Technologies
Traffic Signal System
Improvement Program
Traffic Signal Retiming:
Interconnect signals
Wireless technology
Hardwire interconnectivity
Coordinate signal controllers
Reassign green time
General cost range $760 - $2,700 per intersection
20-25 hours per intersection
Traffic Signal System
Improvement Program
Signal Maintenance Strategies:
Preventive Maintenance
Remedial Maintenance
Staffing Rules-of Thumb
One traffic engineer per 75-100 signals
One signal technician per 40-50 signals
Consultants often supplement staff
Eligible for Federal Aid Funds
Traffic Signal System:
Improvement Program
Utilize new technologies:
ACS Lite (Adaptive Control Software) allows older
software to communicate
Interconnecting signals
Spread Spectrum (wireless)
Actuating Signals
Develop emergency priority corridors
Use of LED signal lamps
LED SIGNAL LAMPS
SAVINGS
Signal maintenance costs
Energy costs
Avg. intersection:
10 vehicular signals/
8 pedestrian
Per vehicular signal
Per pedestrian signal
Per intersection
Annual cost / intersection
Incandescent LED Signals
bulbs
135-150 watts
8-10 watts
70 watts
8 watts
2060 watts
$175/month
164 watts/less
$23/month
$2,100
$276
Average savings of $1,824 monthly/
$40,128 annually per intersection
TESTIMONIALS
A statewide traffic signal retiming
program in California found the
following benefits:
7% reduction in travel time
14% reduction in delay
9% saving in fuel
Benefit/cost ratio 58:1
TESTIMONIALS
A new signal system and improved
signal timing conducted in Abilene,
Texas (a mid-sized urban area)
achieved:
13% reduction in travel time
37% reduction in delay
6% fuel saving
TESTIMONIALS
An advanced traffic control system in
Oakland County, Michigan (a large
suburban area) achieved:
30% reduction in delay
19% increase in peak hour speeds
6% reduction in accidents
33% reduction in stops
Route 51 Corridor
SYNCHRO/SIMTRAFFIC MODEL –
MOE’s
Total Network Performance
PM Calibrated
PM Optimized
Total Delay (hours)
49.1
44.4
Delay/Vehicle (seconds)
117
109
Total Stops
3498
3214
Travel Distance (miles)
2691.1
2514.6
Travel Time (hours)
123.3
113.2
Average Speed (mph)
22
22
Fuel Used (gallons)
198.3
179.8
Fuel Efficiency (mpg)
13.6
14
HC Emission (grams)
514
481
CO Emission (grams)
19643
18991
NOx Emissions (grams)
1603
1491
Vehicles Entered
1744
1686
Vehicles Exited
1276
1246
Hourly Exit Rate
7656
7476
Denied Entry Before
1
3
Denied Entry After
2
0
TRAFFIC SIGNAL OPERATIONS SELF
ASSESSMENT TOOL
Help agencies understand opportunities
for improving their own policies and
practices
Designed for any agency responsible for operation
and maintenance of traffic signals
One hour to complete
No data collection required
Results used anonymously in the 2007 National
Traffic Signal Report Card
To use tool:
http://www.zoomerang.com/recipient/surveyintro.zgi?p=WEB225U6FTB7YM
ADDITIONAL RESOURCES:
FHWA Operations web site:
http://ops.fhwa.dot.gov
Traffic Signal Operation Self Assessment:
www.ite.org/selfassessment
MARC – Operation “Green Light”:
www.marc.org/transportation/ogl/
ACS Lite Software:
[email protected]
PennDOT:
http://www.paits.org/tsop/index.htm
SPC: http://www.spcregion.org/trans.shtml