Strengthen public acceptance of congestion-based pricing of express lanes by preserving the option to use free lanes, maintaining good levels of service, and prioritizing safety.
Experience from California’s State Route 91 value -priced express lanes.
Made Public Date


Orange County
United States

Continuation Study to Evaluate the Impacts of the SR 91 Value-Priced Express Lanes: Final Report


Congestion pricing, also known as value pricing, aims to reduce congestion by increasing the price of tolls on a road in periods of heavy use. The strategy is meant to encourage travelers to use alternatives to single-occupancy vehicle such as car-pooling, mass transit, telecommuting or traveling during off-peak periods. Congestion pricing can be an effective tool for improving traffic flow, with the added benefits of reducing vehicular emissions and providing a source of revenue for transportation projects.

One of the first applications of congestion pricing was in 1995 on the express lanes on State Route 91 (SR 91) in one of the most congested freeway corridors in Orange County, California. To determine the impact of the value-priced lanes, the U.S. DOT and the California Department of Transportation (Caltrans) cosponsored a study that compared conditions before and after implementation. The study, based on more than five years of data, is described in the report entitled “Continuation Study to Evaluate the Impacts of the SR 91 Value-Priced Express Lanes: Final Report” and includes an examination of public opinion of congestion pricing on the SR 91 express lanes. The report shows that motorists' acceptance of a specific congestion-pricing project will be influenced by their ability to choose whether or not to use the toll lanes, by the facility's level of service and by the public image of the managing facility.

Lessons Learned

Congestion-based pricing is the practice of managing demand by increasing tolls during periods of heavy congestion. The outcome of congestion-based pricing projects demonstrates that it is an effective strategy for reducing congestion by creating an incentive for motorists to travel off-peak, car-pool, telecommute, or use mass transit. As jurisdictions face expanding levels of congestion, they may more frequently implement congestion-based pricing strategies as a countermeasure to manage demand.

Public acceptance of a congestion-based pricing facility is one of the factors that underlie its successful implementation. Public acceptance will be influenced by many conditions and circumstances that may change over time. For example, public opinion of the value-priced express lanes on California’s State Route 91 (SR 91) in Orange County, California deteriorated when negative reports emerged about the managing company in terms of putting profit over safety (among other allegations). Whether the allegations were true or not, they damaged the image of the company and by extension the tolling facility. Importantly, however, there were other features of the toll lanes, such as an increase in perceived safety, that appealed to motorists, among others. As time went on, more and more motorists opted to use the toll lanes. A study of the SR 91 toll lanes of the final evaluation suggests that there are key elements related to public acceptance of tolling facilities as follows:

  • Allow motorists the option of using the value-priced toll lanes or the adjacent free lanes. Results from the traveler survey revealed how important it is to motorists to have a choice of tolled versus free lanes. Motorists’ responses to the survey indicate that preserving the option to use the free lanes or the value-priced express lanes was integral to driver acceptance of the toll pricing strategy. Motorists could select to pay the higher toll when they believed it was worth the price to cut their travel time. (Interestingly, motorists’ perceptions of their time savings on the toll lanes tended to be higher than it actually was.)
  • Maintain good levels of service on the value-priced express lanes. The levels of service on the express lanes were high enough for the motorists to equate its cost with the trip time savings. Motorists also believed that the lower levels of congestion meant that the toll roads were safer than the free lanes. The variable pricing managed demand on the express lanes and allowed travelers to drive at the preferred speed. The public’s perspective was that the express lanes off-loaded much of the congestion from the local roads, thus alleviating traffic from adjoining arterials and neighborhood streets.
  • Be aware of, and strive to manage, the risk of decreased public approval of private, for-profit operation of variable toll lanes. Public acceptance of the tolling strategy can be influenced by the image of the company managing the facility. For private, for-profit companies that manage congestion based toll facilities (as well as other tolls), it is important to avoid creating the perception of placing profit over safety. Public approval of the company that managed the express toll lanes in the SR 91 project decreased significantly as an increasing number of reports emerged that alleged the firm had sacrificed safety over profit, did not properly disclose performance and financial information, and blocked the development of alternate travel routes. Results of the survey suggested that such allegations had a negative effect on the initially high level of public approval for the facility, demonstrating that tolling agencies must strive to live up to the public’s expectation for their operations.

The purpose of installing the SR 91 express toll lanes was to mitigate congestion. An analysis of the SR 91 project shows that the lanes have reduced congestion, and that over time more and more motorists were willing to (and did) use the lanes. Key factors to public acceptance of these types of facilities are providing a choice to motorists and preserving good levels of service. These factors support mobility and safety by reducing congestion and are important to the success of congestion-based pricing of toll lanes.

Continuation Study to Evaluate the Impacts of the SR 91 Value-Priced Express Lanes: Final Report

Continuation Study to Evaluate the Impacts of the SR 91 Value-Priced Express Lanes: Final Report
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Edward Sullivan, Department of Civil and Environmental Engineering, Applied Research and Development Facility - Cal Poly State University
State of California Department of Transportation - Traffic Operations Program - HOV Systems Branch

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