Metering lights ready on I-580 Metering lights ready on I-580 (January 31, 2003)

Starting lights could discourage cut-through traffic
by Jeb Bing

Ramp metering lights could be turned on within a few weeks if the Pleasanton City Council gives its traffic engineer the go-ahead to start limiting access to eastbound I-580 at Hopyard, Hacienda and Santa Rita interchanges during the evening rush hour.

The metering light posts are installed, the wiring and computer program are in place and it will only take a reluctant council to allow Traffic Engineer Jeff Knowles to pull the switch.

"My research model shows that by metering the traffic at these on-ramps, we will actually keep more traffic on the freeway and keep it moving instead of some of the ramp-jumping we're seeing that ends up clogging the freeway," Knowles said.

Knowles explained his plan to members of the Tri-Valley Business Council's Transportation Committee before an audience that included Councilwoman Kay Ayala and several Livermore and state officials who question whether Pleasanton should act unilaterally. They said they are not ready to move ahead on metering, which Ayala wants done on a Tri-Valley and regional basis.

But while others continue postponing any action, Knowles said he wants Pleasanton to move ahead to held reduce increasingly heavy cut-through traffic on city streets. He cited statistics that show that a large number of motorists bound for homes east of Pleasanton are using city streets to skirt traffic gridlock on I-580. By metering access to 580 in intervals even as short as four seconds, this traffic would merge faster without freeway traffic putting on the brakes.

Similar efforts along Highway 101 have improved traffic flows there while also reducing congestion on city streets in San Mateo and Santa Clara county cities. Long ago, CalTrans did the same thing on the Bay Bridge, installing metering lights after the toll booths to allow traffic to merge onto the bridge roadway more smoothly.

Knowles wants authorization to turn the metering lights on at the same time that a new merge lane on eastbound 580, now under construction, opens between Santa Rita and El Charro. Without a meter, ramp-jumpers who exit at Santa Rita and then drive across the street and re-enter on the eastbound ramp would have even more incentive to use this system to avoid traffic that is stopped below.

By metering at all three locations - Hopyard, Hacienda and Santa Rita - freeway traffic should move more smoothly in areas east of I-680 where lane configurations change and traffic from both northbound and southbound I-680 flyovers join eastbound 580.

"It's hard to believe that because of congestion and stop-and-go traffic that we are getting less traffic moving east on 580 than there was five years ago," Knowles said. "Five years ago, we had 8,800 cars an hour moving under I-680 compared to only 6,400 today. We're not talking about adding capacity to the freeway. We're talking about improving the efficiency of existing capacity, which ramp metering can do."

Knowles acknowledged that as ramp meters improve freeway traffic merges in Pleasanton, the gridlock conditions could move farther east to Livermore, which has no plans for meters.

"Once we introduce metering and pace the freeway traffic better, the bottleneck could move five miles east of Pleasanton," he said. "But that's five miles down the road, which would free up some of our city streets."

Ayala said she is concerned that ramp metering at Santa Rita could cause traffic jams that affect motorists trying to reach their homes on Pimlico or businesses at that intersection. But Knowles said there is already a backup there during rush hour, and that the meters might reduce the congestion by discouraging the ramp-jumpers.

Knowles also proposed that CalTrans install metering lights on eastbound Highway 84 for southbound I-680 traffic exiting there. The thoroughfare has about a half-mile of two-lane roadway before becoming a single lane over Pigeon Pass and on into Ruby Hill and Livermore. Meters, similar to those used on the Bay Bridge, could improve the traffic flow on the one-lane section by pacing traffic merging from the two eastbound lanes, he said.