There is no established minimum, only a maximum speed. The minimum speed can be set by local municipalities and must be posted by signs.
65
There is no general answer to this question. It will vary according to the state.
No it's 55
Most states don't have truck speed limits. So in a state like Colorado, New Mexico, Arizona, etc. (where the speed limit is 75), trucks can do the speed limit.
65 mph
70mph
There is no such thing as a "residential highway."If you are speaking of a residential street - the usual speed in urban and suburban areas, unless otherwise posted, is 25 miles per hour.
It varies from state to state. You'd have to specify which state(s) you're referring to.
The same as it is for any other vehicle. Speed limits are set by state governments, and the maximum allowed speeds will vary from state to state.
the state with the highest speed limit is Texas
Typically, it'll be whatever the speed limit of that road is. If there are specific laws on the subject, it'll be a matter of state law, not the FMCSR. You'd need to specify a state for a more accurate answer.
It varies from state to state, town to town, road to road.
Speed limit - You must not drive faster than 80 km/h and must observe the speed limit where it is below 80 km/h depending in which state, as learner drivers in Victoria are allowed to do 100km/h.