What’s the holdup?
Traffic is meeting some slowdown on I-680 as construction crews work from Diablo Road to Sycamore Valley Road and from Crow Canyon to Bollinger Canyon to build auxiliary lanes. These lanes connect onramps from one interchange with the offramps of the adjacent interchange, enabling drivers to travel from one exit to the next without merging with through-traffic.
The project includes widening both sides of the freeway to add the 12-foot lanes and also new shoulders.
“People have heard about it for a long time and they’re happy it’s going to occur,” said Mayor Karen Stepper. “But there will be temporary inconveniences.”
She said the town has reported to Caltrans the current difficulty in merging when entering the freeway going south from Diablo Road. An accident took place at that location Wednesday morning, May 24.
The construction work began in April and is scheduled for completion in one year; final landscaping is due in fall 2007. The third segment of the project, from Sycamore Valley Road to Crow Canyon, is not yet funded.
The current work includes expanding the Iron Horse Trail crossing under I-680 at Laurel Drive, which raises more issues for the construction, noted Stepper.
Pedestrians will be able to use the Iron Horse Trail at Laurel Drive throughout the construction although it will be temporarily realigned. Signs will inform users of the detour. Neighbors and trail users may notice an increase of trucks in this area during construction.
“We’ve already negotiated with Caltrans that their trucks can’t use neighborhood streets, they have to use downtown, and not during school times,” Stepper said.
Some trucks will go directly to the construction zone off the freeway so they will not have to use town streets at all, she added.
The freeway needs to be widened on the eastside between Laurel Drive and Diablo Road to accommodate the auxiliary lane and new shoulder. Additional columns will also be added to support the wider bridge structure.
Stepper said another concern has been that sound walls had to be removed for construction. New sound walls will be constructed as permanent masonry walls so will be an improvement for the neighborhoods adjacent to the freeway.
The auxiliary lanes should improve the overall operation of the freeway, noted a project report, providing a longer merging distance for vehicles entering and exiting the freeway. “The new lanes will eliminate on-ramp delays by providing exclusive travel lanes for vehicles entering the freeway,” according to the report. “This will result in much smoother weaving on and off the freeway.”
Construction hours are generally between 7 a.m. and 3:30 p.m. Monday to Friday, but some work will occur until 5:30 p.m., according to the Contra Costa Transportation Authority. Restriping work and barrier placement on 680 will take place at night, and some weekend and night work will be necessary. Work necessitating lane closures will take place at night.
The $59.7 million project for all three segments is being funded by Measure C, the half-cent gas tax passed in 1998 for transportation improvement; the Surface Transportation Program; Southern Contra Costa Regional Development fees; Tri-Valley Transportation Development fees; and State Transportation Improvement fees.
