Changes coming eventually to 580-680 interchange in Dublin

QI repeatedly witness rear- end accidents with multiple cars almost every weekend at the Interstate 580 west ramp to south Interstate 680 near Dublin. Constant cross traffic between cars from I- 580 to I- 680 forces drivers to make sudden stops. These accidents have caused many injuries and damage, and traffic delays since Caltrans reconstructed this interchange years ago. I even saw an accident involving a CHP vehicle.

Does Caltrans track how bad the situation is? We need a dedicated ramp to avoid crossing traffic or at least put up warning signs to remind drivers to slow down and that sudden stops are expected at this interchange. — Wing Lai, San Ramon

AYes, they know how difficult it is here. Next year, the Alameda County Transportation Authority will begin studying possible improvements, looking at adjacent projects such as the widening of Highway 84, the 84- 680 interchange im- provements, 680 express lanes and their impact on 580- 680.

QIs there any new word on plans to rebuild the I- 680-Highway 4 interchange in Contra Costa County? Highway 4 between 680 and Highway 242 is awful, and last I heard they were still trying to line up money to do something about it. … This has got to be the worst congestion in this part of the East Bay. It’s horrific. — J.B., EdWest and more

AIndeed it is. Contra Costa officials hope to have $135 million in hand to begin work in June or July to cover the cost of one phase of work. But the total cost could exceed $ 400 million. If voters approve higher bridge tolls, a chunk may be earmarked for this interchange. And the higher state gas tax may help. Work has been split into five phases for construction of a three-level interchange.

Up first is widening Highway 4 in the median from Glacier Drive to the east of 242. It will extend the HOV lane from 242 to the Grayson Creek Bridge.

This will add 2 miles to the west of the existing carpool lane. The project also will widen five structures and replace Grayson Creek Bridge, which is too low to handle large storms.

QI was approaching the Bay Bridge toll plaza and a lane- splitting motorcycle came up on my passenger side. Without slowing, he slammed the rear-view mirror on that side of my car. Very startling, and then I saw him do it to another car ahead of me.

Why would one do this? It makes it harder to see lane- splitters without the benefit of that side mirror. — Betsy Thomas, Albany

AOnce might have been an accident, but not twice. Mr. Motorcyclist, please chill out.