Transportation's Role in Reducing U.S. Greenhouse Gas Emissions ...

Transportation’s Role in Reducing U.S. Greenhouse Gas Emissions: Volume 2
(see “feasibility”). Other strategies, such as Active Traffic Management, are still in the
development phases and could take 10 to 20 years or more to reach full deployment even
with aggressive funding and implementation activities. To maintain the benefits of
operational improvements over time, signal timing must be readjusted regularly as traffic
conditions change; the Institute of Transportation Engineers suggests reviewing signal
timing annually (ITE, 2009).
Cost-Effectiveness
Costs of traffic management strategies vary greatly. Costs range from as low as $2,500 to
$3,100 to retime individual intersections, to on the order of $5 to $10 million for
establishing an Emergency Response Center or a Transportation Management Center for a
large metropolitan area, plus $0.5 to $1.5 million annually in operating costs (ITS Unit
Costs Database, reported in Cambridge Systematics, 2008). If implemented on a
nationwide basis, ramp metering is estimated to cost between $1.3 and $7.5 billion; signal
control management between $2.5 and $17 billion; and incident management between $2.2
and $13 billion, depending upon the extent of the metropolitan highway system covered.
The costs of deploying Active Traffic Management or Integrated Corridor Management
nationwide are estimated to range from $11 to $26 billion, again depending upon the
extent of the highway system covered (Cambridge Systematics, 2009). Costs for traffic
management strategies will typically be borne by public sector transportation agencies (or
toll facility operators) and financed through State, regional, and local transportation
funding sources.
The cost-effectiveness of traffic management strategies depends strongly upon whether
induced demand effects are considered in estimating the benefits. Without induced
demand effects, the cost-effectiveness of traffic signal retiming (measured in terms of
GHG reductions) is estimated to be quite good – about $12 per tonne CO2e reduced
considering implementation costs only. 13
More advanced traffic management strategies
have varying levels of cost-effectiveness. Ramp metering and incident management
strategies appear to be among the more cost-effective with estimates in the range of $10-40
per tonne GHG reduced over the 2010 to 2050 timeframe. Active Traffic Management and
Integrated Corridor management are somewhat less cost-effective (in the range of $100
per tonne) as is signal control management (in the range of $200 per tonne) (Cambridge
Systematics, 2009). Including benefits to travelers in the form of vehicle operating-cost
savings, cost-effectiveness is estimated to be in the range of -$150-170 per tonne GHG
reduced over the 2010 to 2050 timeframe, with Active Traffic Management and Integrated
Corridor management in the range of -$90-140 per tonne and signal control management
in the range of -$40 to +$50 per tonne. Vehicle Infrastructure Integration is estimated to
range from $130 to $160 per tonne for implementation costs only, or -$20 to -$40 per tonne
considering operating cost savings to travelers. These estimates do not include the value
of time savings.
13 This estimate applies the benefits extrapolated from the previously referenced Portland study,
and assumes costs of $3,000 per retiming annualized over five years.
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