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Q: Good Grief! I was traveling on Interstate 580 between Tracy and Livermore last week when I hit a transition between the freeway and concrete overpass. The transition was so rough that my GPS fell off the holder.

When is this going to be fixed? The freeway is quite smooth now that that has been paved, but the transitions are horrible. This is also a problem in the other direction, but at least my GPS didn’t come flying off.

Warren White, Livermore

A: This won’t make you feel better, but there are a lot of poor souls who join the “Good grief” chorus.

Q: I drive I-680 between Livermore and San Jose and on I-680 at the Capitol Avenue exit in San Jose, there is a big “bump” where the freeway lanes meet the overpass. When you’re traveling 65 mph and hit the bump, you “catch air” and everything goes flying. … These bumps are severe, pound your suspension and just about rips the wheel from your hands. … I drive a sports car, and when my tires hit these gaps where asphalt meets concrete on overpasses, the entire car shudders and jumps. Does Caltrans acknowledge that these transitions are a hazard?

Jacque Sommers, Jimmy Bickford, Colette Farabaugh and so many more

A: Oh my, yes, but Caltrans says it’s a difficult one to resolve. There are tens of thousands of joints in California where concrete meets asphalt. After paving, it’s usually a smooth ride but over time, it could be wear-and-tear, settlement or many different reasons why bumps start showing up.

It is non-stop work every year on many highways. Said Sam-a-Roadshow-Advisor: “During my 26 years career with Caltrans, I lost count as how many projects we performed to fix the joints. Some are an easy fix; others are tough to fix.”

Concrete bridges sit on solid foundations, frequently supported by piling, which reaches bedrock. Roads are usually asphalt, and are placed on softer, more compressible soils. Over time, roadways settle faster than bridges and a bump grows right at the transition point.

Solutions? Pump grout underneath the freeway might fix the problem for a while. Use concrete slabs to span the gap between the overpass and freeway lanes, but they are expensive and not always utilized. Even with a concrete slab, settlement will still cause a bump.

The trend today is to try to make the surface of bridges asphalt. The bridge deck may still be concrete, but engineers want to overlay the bridge with about a thin layer of asphalt which today is more durable.

Good grief. Voters have approved so many tax and bond measures to improve our roads and deserve better.


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