NCHRP Synthesis 686 was completed in 2011. Multiple case studies were examined. The following pricing concepts were reviewed:
- Conversion of high-occupancy vehicle (HOV) to high-occupancy toll (HOT) lanes
- Variable pricing on new or rehabilitated facilities
- Variable pricing on existing toll facilities
- Area wide or cordon pricing
- Distance based pricing or mileage fees
- Variable pricing applied to parking
The overarching goal of this project is to help state, regional, and local decision makers and planners to:
- Understand a range of road pricing concepts
- Determine which concepts may be most applicable, effective, and acceptable in light of the local environment and objectives
- Provide lessons on communicating pricing proposals and developing project plans for best chances of successful implementation
- Integrate pricing plans into regional and state planning processes to advance implementation
This report focuses on road pricing where the primary objective is the reduction of congestion and associated problems while potentially supplementing or replacing declining traditional sources of transportation finance. The report aims at the audience
of planners who are interested in knowing more about potential, status, and key planning considerations for road pricing.
Conversion of HOV lanes to HOT lanes
- Early evaluations in San Diego (I-15 FasTrak) and Houston (US-290 and I-10 QuickRide) indicated that HOV to HOT conversions can increase lane use by 21 to 24 percent and save HOT lanes users 11 to 20 minutes in travel time.
- Impacts on general purpose lanes were positive in Houston and Minneapolis (I-394 peak period speeds were up 15 percent).
- In Orange County, California two new lanes were added in each direction on SR-91 with variable tolls priced by time of day and day of week. The additional physical capacity resulted in free-flowing express lanes that carried over 40 percent of peak period traffic. Benefits, however, were limited as travel demand continued to grow.
- In the Washington DC metropolitan area, variable pricing projects (I-95/I-395 and I-495 HOT lanes) have been forecast to increase transit use, slightly decrease HOV use, slightly improve speeds in mixed-use lanes, and increase vehicle miles traveled (VMT). Modeling efforts suggest that a network of variable priced lanes can be more effective than the simple sum of individual projects.
- A survey taken the year after the Lee County, Florida, toll discount program showed that 71 percent of eligible drivers shifted their time of travel at least once a week under 25 cents off-peak toll discount (elasticity estimates ranged between –0.36 and –0.03 depending on the time of day).
- Travel time savings of up to 20 minutes were observed with PANYNJ tolls. 7.4 percent of passenger trips and 20.2 percent of truck trips changed behavior (travel time, mode).
- Smaller, independent trucks were more likely to shift to alternative routes or travel times due to limited ability to pass along the increased cost to customers. (e.g., Illinois Tollway). Note that some truckers may not be able to shift travel times because of inflexible delivery schedules (e.g., PANYNJ experience).
- In the City of Singapore, the number of vehicles entering the charging zone dropped by 24 percent and average vehicle speeds increased by approximately 28 percent after area wide electronic pricing was introduced in 1998.
- In London, implementation and expansion of cordon pricing in 2007 reduced the number of vehicles entering the charging zone by 14 percent, decreased journey times by 14 percent, and increased average travel speeds by approximately 30 percent. Although the system initially increased morning peak period transit use by approximately 40 percent and resulted in sustained traffic reductions that lasted for more than five years, traffic conditions are of increasing concern as auto use, bus traffic, and construction increases, and changes to toll levels have been limited. In London, it was found that a 10 percent increase in user auto travel costs (excluding parking) resulted in a 4 to 5 percent reduction in auto trips. Car trip to price elasticity ranged from –0.4 to –0.5.
- In a Puget Sound trial, peak period mileage fees of 40 to 50 cents per mile on freeways (10 to 15 cents during off-peak) and 20 to 25 cents per mile on non-freeways (5 to 7.5 cents during off-peak) reduced VMT by approximately 10 percent.
- In Oregon, a distance based pricing concept that charged 0.43 cents per mile during off-peak periods and up to 10 cents per mile during peak periods reduced VMT by 11 to 16 percent.
- In San Francisco, the SFpark program used on- and off-street parking pricing to encourage use of garages/lots and balance the use of metered parking. Variable parking meters with progressive pricing (low first 2 hours with higher third and fourth hours) resulted in decreased occupancy and duration of on-street parking at the Port of San Francisco. Researchers noted that a “rule of thumb” for price-demand elasticity is –0.1 to –0.3, meaning a 10 percent increase in price reduces demand by about 1 to 3 percent, including shifts to other available parking (on and off street), alternative modes, or forgone trips.