A first-of-its-kind "dynamic congestion pricing" mechanism helping alleviate traffic along one of San Diego's busiest freeways is receiving widespread attention from cities all over the world anxious to solve their own traffic woes.
A team led by San Diego State University civil engineering professor Janusz Supernak is in the final stage of assessing the effectiveness of the approach that may have an international impact on traffic management.
The Interstate 15 Value Pricing Project was designed to make more efficient use of the freeway's high-occupancy vehicle (HOV) lanes by allowing solo drivers to use it for a fee. Detectors embedded in the pavement of the express lanes report traffic volume data in six-minute increments. When that volume exceeds an acceptable level, an algorithm calculates the price for which solo drivers can buy access to the HOV lane, a cost Supernak said could range between 50 cents and eight dollars. An electronic toll collection system at the HOV lane entrance reads a transponder mounted on the car windshield and the specified amount is automatically deducted from a pre-paid account.
The resulting funds, about $2 million a year, are earmarked to finance The Inland Breeze, a bus service expressly for I-15 commuters.
Supernak said San Diego is the first city in the world to attempt this approach, financed by a grant from the Federal Highway Administration and managed by the San Diego Association of Governments. Ten other cities are scheduled to follow, led by Houston and Miami. Officials in several European and Asian countries are closely following San Diego's experience with the traffic management plan.
Evaluation of the plan involves more than a dozen individual studies covering issues ranging from usage patterns and air-quality measurements to effects on business and development patterns. The fairness issue was also of particular concern.
"A series of public hearings were held to inform the public about the project's potential benefits to both users and non-users," Supernak said. "A lot of work went into determining a proper fare level."
Supernak added one of the positive effects of the plan has been an increase the number of carpoolers.
"People who considered paying for the use of the HOV lane as a solo driver apparently realized, 'I could do this for free in a carpool,'" he said. "Because of the growth of the region, there has been an increase in the total number of cars, but the HOV lanes are being utilized much better that before the Value Pricing Program was started."
San Diego State University is the oldest and largest higher education institution in the San Diego region. Since it was founded as a teacher-training program in 1897, it has grown to offer bachelor's degrees in 76 areas, master's degrees in 58 areas and doctorates in 11. The more than 30,000 students participate in an academic curriculum distinguished by direct contact with professors and an increasing international emphasis that prepares them for a global future.
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