4 ms·Speed limits usually are for the worst case scenario: an old car, foggy and rainy day.by neves 8y agoSpeed limits usually are for the worst case scenario: an old car, foggy and rainy day.ivalm 8y agoSure, and for most people these speed limits are inappropriate. Forcing everyone into the worst common denominator is not a good idea for automated systems.hopler 8y agoNo, you should drive extra below speed limit on days with low visibility or reduced control.