I-5 Meter Systems Unveiled

The latest additions to San Diego County’s freeway metering system have opened on four southbound Interstate 5 on-ramps in Del Mar, Cardiff and Solana Beach.

The systems, which restrict the flow of cars from on-ramps onto major interstate and state highways during rush hour, contain sensors embedded in the freeway that measure the speed and volume of traffic along a given stretch.

Data is flashed to a computer at the Traffic Operations Center at Caltrans’ Old Town district headquarters, then signaled to on-ramp traffic lights.

While the metering systems have been placed on several other freeway and state routes in San Diego County, the new systems that began operating last week at the Via de la Valle and Del Mar Heights southbound on-ramps in Del Mar, at Manchester Avenue in Cardiff and at Lomas Santa Fe Drive in Solana Beach are among the first on Interstate 5.

In downtown San Diego, a metering system controls the southbound Interstate 5 on-ramp at 5th Avenue. Most metered on-ramp systems involve two regulated lanes, including one for single passenger cars and another used as an express lane for cars with multiple passengers.

Caltrans has now installed 85 of the systems along county roads since the first was put in place along California 94 in the mid-1970s. But the state transportation department is now accelerating installations of the metering system and plans to have 286 of them in the county’s freeway grid by 2000, a Caltrans spokesman said.

Caltrans sees the acceleration of new on-ramp metering systems as a way of coping with San Diego County’s increasingly overburdened freeway system and as a holding action until new freeway projects are completed.