65 mph
70 mph
55mph
70 MPH on Interstate Highways.
70 MPH
wrong.
70mph on some rural interstate highways
Yes, many state highways have a minimum speed limit.
70 mphAdditional: Use caution when applying this answer to your own state. This sounds like the un-posted maximum on Interstates or main arterial rural highways. I seriously doubt that 70 MPH is the allowable maximum EVERYHERE in a rural area.
The maximum speed limit in Florida is 55 mph, except where otherwise posted. Speed limits are 70 mph on some rural interstate highways.
The minimum speed on major routes (if any) varies by state. As an example, in many jurisdictions the minimum speed on a 65 MPH Interstate is 45MPH. Most states have a catch-all rule that states you can be ticketed for driving at any speed that is so slow as to impede the flow of traffic.
The maximum speed would be only fifty five on all major highways because that is the legal speed limit.