Appendix A. Summary of Study Project Reported Travel Findings

Study/Project	Results	Conclusion	Major Caveats/Limitations
Simulated Pricing Field Demonstrations
Oregon Mileage Fee Concept and Road User Fee Pilot Program	10% reduction in total VMT 13% reduction in peak hour VMT Peak hour mode choice influenced by the pricing	Mileage price incentives can be expected to impact travelers’ total amount of driving, the timing of their trip making, and, potentially, their mode of travel	None reported
Puget Sound Traffic Choices Study	7% reduction in total weekly vehicle trips 12% reduction in weekly VMT 8% reduction in total weekly travel time 13% reduction in weekly VMT on tolled roads	Motorists made small-scale adjustments in travel that, in aggregate, would have a major impact on transportation system performance Households that modified their travel did so in many different ways: fewer and shorter vehicle trips, alternate routes and times of travel, or linking trips together to reduce vehicle use altogether	Responses to congestion charging may be underestimated in so much as some households who may have been inclined to avoid the peak period charges did not have the flexibility to do so
Commute Atlanta Mileage Based Value Pricing Demonstration	3% reduction in total VMT	Little if any project impact. Observed VMT reduction thought to be a function of non-project related changes in travel behavior	Inter- and intra-household variability and demographic instability obscured any project impact Higher income respondents were somewhat over-represented in the survey
Before-After Project Evaluations – U.S.
Minnesota I-394 MnPASS HOT Lanes	Up to 5% increase in peak hour corridor throughput 6% average increase in speeds in general purpose lanes Speeds increased in the general purpose lanes and MnPASS lane for many locations Travel times generally unchanged or slightly increased Project benefits distributed relatively evenly amongst population	The public supported the HOT lane concept MnPASS users were satisfied with toll operations	None reported
San Diego I-15 HOT Lanes	48% increase in express lane traffic volumes 76% of FasTrak customers would leave at a different time in the morning if there were no FasTrak.	I-15 pricing project alleviated congestion on the I-15 main lanes by redirecting an increasing share of volume onto the I-15 express lanes Dynamic pricing structure was able to create desirable redistribution of a portion of express-lane traffic from the middle of the peak to the shoulders	Exogenous factors played a more significant role than the project in regard total traffic increases in the I-15 corridor
Before-After Project Evaluations – International
The Stockholm Trial	16-24% reduction in peak hour traffic volumes 14% reduction in VKT in charging zone 33-50% reduction in peak hour average queue wait times 3% reduction in average journey (travel) times	The project was successful in managing congestion and increasing flow and accessibility	The impact of other projects and fuel price changes were not completely controlled
	Car trips across the pricing zone decreased by 20 percent No project-attributable changes in walking, bicycling, telecommuting or carpooling Trip chaining increased slightly	The pricing project shifted trips to transit	Exogenous factors, including fuel price changes and seasonal variation limit the strength of conclusions
	6% increase in total transit ridership 4% decrease in the proportion of transit users that are satisfied with service quality	Increases in transit use met or exceed expectations Goals for maintaining transit rider satisfaction were not achieved due to crowding and reduced schedule adherence	Increases in transit uses may also have been impacted significantly by fuel prices and economic development
London Congestion Pricing	15% reduction in VKT after first year 18% reduction in number of vehicles entering the pricing zone 25% reduction in delays 14% reduction in journey times 21% increase in speeds	The project has succeeded in its fundamental objectives in reducing congestion	Impossible to precisely and definitively isolate project impacts from exogenous factors impacts
	37% increase in passengers entering central zone by bus 30% decrease in excess bus wait time in first year 20% reduction in bus kilometers not operated due to congestion	Transit has accommodated significantly increased passenger levels with limited adverse impacts Transit performance has been improved in some respects as a result of reduced roadway congestion and transit service enhancements	Exogenous factors have influenced transit ridership and performance but some estimation of project-specific impacts are possible
	(Central charging zone) 50-60% of trips formally made by car now made by transit; 20-30 percent driving around the charging zone; 8-10 percent bicycling, motorcycling or walking; <1% eliminated trips; and <1 shifted car trip to non-priced times	The charging scheme has resulted in significant travel behavior changes, with most trips shifting to transit	Being based largely on surveys, despite best efforts, some groups are likely over or under-represented
Singapore Area Pricing	44% reduction in traffic volumes into the priced zone Share of HOV 4+ trips increased from 8 to 19%; bus share increased from 33 to 46% A.m. peak speeds inside priced zone increased by 20% or more Speeds increased 10% on inbound roadways leading to the priced zone Motorists shifted trips to non-priced times and routes	The pricing projects, coupled with other strategies, have been effective in providing lasting, significant reductions in traffic congestion	None reported.

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