55
45 MPH
scalar
An Autobahn is basically a German version of a highway. ******** A VERY high speed highway- such as an expressway or an interstate highway.
70
69
A US highway is an all access highway, like a main road; it includes businesses, houses, and direct intersections. Top speeds on the average US highway are 55 mph. An interstate highway is a limited access highway that is meant for commute. It includes no property entrances, and interchanges at high speed. Speeds range from 65 to 75 mph (about 90 to 105 km/h).
A scalar, since no direction is specified.
around 65m.p.h on the straightaways
55, in the city, 65 or 70 outside of the city. (U.S.)
The highest speed limit I know of on an Interstate highway in the U.S. is 75 MPH, but that varies.
70 mph - but some states do not allow that speed.
Depends which state you're in. Texas has the highest Interstate speed limits, with some sections being allowed up to 80 MPH.