35 years ago I regularly drove a clapped out MkII Jaguar at speed on heavily corrugated all weather laterite roads in central Africa. The roads are heavily cambered for the wet which made negotiating corners at speed possible. There was though a distinct sense of not quite being in control. On at least one occasion an oncoming vehicle left us driving through a right hand bend on the right hand side with full power and full left lock. Apart from the rear cantilever springs falling out of their chassis mounts a few times and the contacts breaking on a voltage regulator there were no problems. There was also enough power to drag the front wheels out of ditches if resting on the chassis. My MGA sports car with rock hard suspension was a different, back breaking, proposition.
These days, I plod along in the Canter. Doesn't seem to matter how long it takes me. I seem to get there ok. The parabolics help. I try to attain more comfort than higher speed. I can't imagine trying to cruise over the top of corrugations with our 4.5 tonne for long distances. I'm also mindful that I'm 30,000km from home and support.
As well as tyre pressure 4wd helps a bit. My analysis is it drives the front wheels over the corrugations rather than pushing the wheels into them. Similarly, for intermittent corrugations I find it easier to drive through them rather than trying to slow in the middle of them. Braking is bad news - just as well I don't drive on the brakes anyway. The exhaust retarder is my friend.
For us there's usually a "right" speed for regular corrugations (like those in the pictures) which is relatively slow. The nature of the corrugations (height, frequency, hardness) and thus the speed depends on the other traffic is (trucks, buses, consumer 4wds, etc) and on the underlying road bed (sand, laterite, gravel, etc) as well as straightness / hilliness. Something about the relative height / frequency of the corrugations in the photo suggest to me they would be uncomfortable at any speed and destructive at high speed.
For hilly / twisty roads the worst corrugations usually occur where other vehicles are under power, going up hill or accelerating out of corners. As well as when they brake. I usually manage to drive so I'm not surprised by the changes and enter them at about the right speed. "Out of phase" with other drivers I guess.
Time of day helps as the sun can highlight or hide changes in corrugations. We tend to be more cautious when we have difficulty reading the road.
FWIW the most uncomfortable roads for us seem to have been concrete roads with tarmac on top. Long frequency undulations with a bump at every join plus potholes with hard edges. It was a German Autobahn that finished off one of our original rear leaves. Strangely, the culverts (drains under roads) on some Swedish roads slowed us, they'd subsided and occurred roughly every 100m. Hardly worth accelerating to slow down for the next one. How rough was unpredictable. Worse than those half round speed bumps. Unfinished Mongolian roads with 3" sharp stones were diabolical but usually had old tracks alongside them.
I'm the proud owner of one hacksaw blade which has been used many times in the last couple of years and should see us home - not to suggest we haven't had problems but its generally all about technique whether its hacksaw or driving.
