Unless a different limit is posted, what is the maximum speed limit on a two-lane undivided highway in California?

Why

California's default maximum on most highways is 65 mph, but two situations drop it to 55: a two-lane undivided highway, and any vehicle towing a trailer. Seventy is not one of the handbook's default limits; a higher number applies only where it is posted. These figures are ceilings, not targets: the Basic Speed Law forbids any speed beyond what the conditions of the moment make safe, so traffic, weather, the road surface and the presence of bicyclists or pedestrians can make the legal speed much lower than the number on the sign. Driving much slower than the limit can also get you cited if you block the normal flow of traffic.