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Assessment of Fuel Economy Technologies for Medium and Heavy ...

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truck-specific congestion pricing such as the varying time-<strong>of</strong>-day gate fees implemented at the<br />

Ports <strong>of</strong> Los Angeles <strong>and</strong> Long Beach.<br />

Congestion pricing could affect truck fuel consumption by:<br />

Shifting trips to less-congested <strong>of</strong>f-peak hours;<br />

Reducing congestion <strong>for</strong> trucks continuing to operate during peak periods;<br />

Reducing overall goods movement <strong>and</strong> related truck traffic due to higher costs; <strong>and</strong><br />

Shifting logistics patterns – e.g., leading industries to establish consolidation centers on the<br />

edges <strong>of</strong> urban areas to reduce truck activity within the congested area.<br />

Area-wide congestion pricing is applicable to freeways <strong>and</strong> major arterials where there is<br />

significant congestion. Cordon pricing strategies are only applicable in major urban areas with<br />

significant congestion. The limited geographic applicability <strong>of</strong> these two scenarios limits the fuel<br />

reduction potential. Area-wide congestion pricing has greater potential since it is estimated that<br />

nearly 30 percent <strong>of</strong> urban VMT occurs at level <strong>of</strong> service E or F. Cordon pricing <strong>of</strong> metropolitan<br />

area central business districts, however, is estimated to affect only 3 percent <strong>of</strong> total VMT<br />

nationwide. Furthermore, evidence suggests that there will be little, if any, overall impact on<br />

total truck traffic (as the added costs are likely to be marginal, or the option <strong>of</strong> moving to the<br />

<strong>of</strong>f-peak period acceptable), but rather that the benefits will occur from trucks operating under<br />

improved flow conditions, <strong>and</strong> there<strong>for</strong>e using less fuel due to idling or stop-<strong>and</strong>-go operations.<br />

This will have a larger impact on smaller urban trucks since larger long distance trucks operate<br />

mostly on uncongested highways.<br />

It should be noted that while reducing congestion should improve fuel economy up to a point<br />

(e.g., increasing average speeds from 10 to 20 or 20 to 30 mph), truck fuel consumption rates also<br />

tend to increase at higher speeds (over 45-55 mph), <strong>and</strong> there<strong>for</strong>e, increasing speeds from<br />

mid-range congestion (30-40 mph) to free-flow highway speeds may have a negative fuel<br />

economy impact. Congestion is likely to affect urban service <strong>and</strong> delivery movements more than<br />

long-haul freight, <strong>and</strong> there<strong>for</strong>e it is the fuel consumption characteristics <strong>of</strong> smaller trucks that<br />

are most important.<br />

If congestion pricing is implemented only on a limited basis (e.g., only freeways), diversion <strong>of</strong><br />

traffic to other nontolled facilities is likely to be a significant concern because <strong>of</strong> the impacts on<br />

neighborhood <strong>and</strong> local traffic. Increases in VMT on alternate routes could <strong>of</strong>fset the fuel savings<br />

achieved from reductions in VMT <strong>and</strong> congestion on the facility itself. There<strong>for</strong>e, congestion<br />

pricing will be most effective at reducing fuel consumption if it is implemented universally (on<br />

all major roads in an area).<br />

While reducing congestion can save fuel, there is an implicit limit on these savings, bounded by<br />

the total fuel wasted in existing congestion. In this analysis, a sketch-level estimate is made <strong>of</strong> the<br />

total fuel ―wasted‖ by trucks, <strong>and</strong> there<strong>for</strong>e the potential upper bound benefits <strong>of</strong> congestion<br />

relief strategies. This analysis only considers the fuel savings from improved traffic operations,<br />

<strong>and</strong> not any reduction in fuel use due to an overall decrease in dem<strong>and</strong>.<br />

Findings: Most studies <strong>of</strong> the impact <strong>of</strong> congestion pricing have focused on all traffic, rather than<br />

distinguishing impacts on personal vs. commercial vehicle traffic. A study <strong>for</strong> the U.S.<br />

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