Concrete ‘dips’ on highway can send drivers airborne
Q
Interstate 280 south from Sand Hill Road has several serious gaps where the asphalt has sunk at certain overpasses. There are a few heading north as well, but those are smaller.
Someone put up a little sign shortly before one of these gaps south of Page Mill that says “bump.” Someone is going to lose or damage their tire, wheel, suspension or car hitting one of these gaps. — Jim Kleinberg and many more
A
That “bump” sign is back? Caltrans put one up a couple of years ago to warn drivers, smoothed out the transition at the concrete overpass, but now it’s rough as ever.
Q
There’s been a 3-inch drop-off on southbound I-280 in the Los Altos area where it goes to concrete for several years. It was supposed to be fixed, never has.
Caltrans also needs to fill in the pavement over every I-280 overpass or bridge between Highway 101 in San Jose to north Interstate 680. All lanes are just brutal. Now, when I go to Fremont, I take Interstate 880, but it’s not much better. — Mike D’Amelio, San Jose
A
Mike spent around $2,000 last year to repair his suspension. Here’s why there are significant bumps on freeways at bridges. When a freeway is repaved, the roadbed surface may be raised or lowered as a result.
The vertical clearance between a freeway and a bridge that passes over the freeway cannot be less than 16 feet. If repaving would reduce that clearance below 16 feet, then the freeway will not be repaved under the bridge. Concrete is used because it can handle water better.
Q
Which of the four lanes on south I-280 is the least severe to cross over near El Monte Road? — Gary Moitozo, San Jose
A
None. So slow down when you spot the “bump ahead” sign.
Q
On Highway 85 where it crosses Great Oaks Boulevard, there is an extremely dangerous spot where the roadway pavement meets the concrete of the overpass. The difference in height is severe.
One day I saw a truck go airborne. Caltrans put orange signs saying “uneven road surface” but this is clearly a weak Band-Aid. — Dean Coleman, San Jose
A
It is. And let’s motor over to Highway 87.
Q
On sections of Highway 87 north of Taylor Street, there is quite a sharp dip onto the older pavement. It covers all lanes, so I can’t avoid it. Any plans to even out the ride? — Dana Tucker, San Jose
A
Yep. Most likely the state will try to provide a smoother ride once winter rains end.