TRAFFIC SIGNAL
MANAGEMENT
PURPOSE

Purpose: Foster understanding
through development of educational
outreach materials



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Illustrate benefits and basic techniques
Share information on new technologies
Highlight need for multi-municipal
cooperation
Target Audience:
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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

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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


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Standardization of equipment
Remove unwarranted signals
Install and maintain equipment
properly

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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

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Time based coordination

Closed Loop Systems
Centrally Interconnected & Controlled
Systems

Personal computer (PC) based
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Traffic Operations Centers
Detection & Actuation
Strategies

Fixed Time Operations
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Semi Actuated Operations

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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

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Most flexible
Best for isolated signals
GOALS

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Centralized coordination of signals
Coordinate signal operations over
jurisdictional boundaries

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Integrate traffic flow over larger areas
Corridor Administrator to set up and
implement


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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


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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:
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Preventive Maintenance
Remedial Maintenance
Staffing Rules-of Thumb


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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:

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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
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SAVINGS

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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

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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
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Traffic Signal Operation Self Assessment:
www.ite.org/selfassessment

MARC – Operation “Green Light”:
www.marc.org/transportation/ogl/
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ACS Lite Software:
raj.ghaman@fhwa.dot.gov
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PennDOT:
http://www.paits.org/tsop/index.htm
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SPC: http://www.spcregion.org/trans.shtml