This is copied from the Idaho Statute #49-464 regarding Idaho speed limits. (c) Seventy-five (75) miles per hour on interstate highways;
(d) Sixty-five (65) miles per hour on state highways;
(e) Fifty-five (55) miles per hour in other locations unless otherwise
posted up to a maximum of sixty-five (65) miles per hour.
(3) The maximum lawful speed limit on interstate highways shall not
exceed sixty-five (65) miles per hour for vehicles with five (5) or more axles
operating at a gross weight of more than twenty-six thousand (26,000) pounds.
The speed limit doesn't change, but you are expected to make a reasonable adjustment to your speed to compensate for the conditions. So basically, as fast as you can go at or below the speed limit without getting into a wreck.
The safest maximum speed for that road
The fastest vehicle.
It depends on conditions. It has a high speed in Metals with high temperature.
The human speed limit has not yet been identified but one way to be sure is to calculate the energy muscle can provide for our legs. For example, in a 100m race, the amount of kinetic energy can be calculated. Usain Bolt's kinetic energy for the world record is about 369.56J. So, in order the know the max limit of human speed ,just get the max energy our body can provide at an instance.
There are several Interstate Highways with a 75 MPH speed limit at various points throughout their span, but there isn't one which has that speed limit at every single point.
60
65
70
The speed limit on Interstate 90 in South Dakota is 80 mph or 128.7 km/h, except in city limits where the speed limit is lower, usually 55 or 65 mph.
50
scalar
As close to the posted speed limit as possible.
The highest speed limit I know of on an Interstate highway in the U.S. is 75 MPH, but that varies.
70
70 MPH on Interstate Highways.
69