paulj wrote:
Many miles of Interstate were built with concrete slabs which have tended to shift with use. Often one end tips down a bit, the other up. When a heavily loaded truck tire crosses from the up end of one slab to the next, it drops and puts further downward pressure on the next. The result is a sawtooth surface. If the period of that surface coincides with the RV suspension tuning the ride can be very rough.
I've read that the cause is due to the harmonic frequency of semi-truck suspensions coinciding with the spacing of the gaps between slab sections. Sounds plausible - dunno. Whatever the cause, concrete slab roads in this condition are a disaster. In the past, we had the cords break in a tire on a near new pickup truck in NorCal on I-5. The tire had large bubbles all over it. All 4 tires got replaced under warranty when we got home. On another trip on same I-5, same thing happened twice on the same trip. When it happened the 2nd time, we were extremely lucky to find a wrecking yard nearby that we limped to. They had the same wheel/tire size available and we were able to get back on the road quickly.
The sharp thump, thump, thump is really hard on tires. If I ever encounter a road with concrete slabs like that again, I'm gonna slow waaay down and take a detour if possible, esp. if towing the TT.
The worst road I've seen anywhere on the planet has to be I-680, a highway from hell around the east side of SF. Six lanes of high speed driving with crazy drivers on a non-stop super-rough surface. Our truck & TT were shaking so badly I thought they were going to explode. Not possible to slow down. Wouldn't ever do that again!!
So how can Oregon have no sales tax yet have some pretty decent roads?
Have towed our TT lots in CA and have never seen a radar trap anywhere. On the interstates I hang with the truck traffic at up to 65 mph (due to ST tires). On secondary hwys I drive up to 65 depending on what other traffic is doing. Driving at 55 feels like you're standing still. It gets fun when the semi trucks slow up the hills while I'm able to hold the speed and they disappear out of view in the mirror. Then down other side they catch up and fly past while I hold at max 65. Can be back 'n forth for many miles sometimes... :)