Depends which state you're in. Texas has the highest Interstate speed limits, with some sections being allowed up to 80 MPH.
70 mph
70 mph - unless otherwise posted.
70 mph - unless otherwise posted.
70 mph - unless otherwise posted.
70
69
70mph on some rural interstate highways
70 mph - but some states do not allow that speed.
scalar
The maximum speed limit in Florida is 55 mph, except where otherwise posted. Speed limits are 70 mph on some rural interstate highways.
It varies from state to state. You'd have to specify which state(s) you're referring to.
In the US, the maximum speed on an interstate highway is 70. Until recently, there were a couple of stretches of highway that were limitless.
That varies by state. I know in Raleigh, it's 65 MPH on I-40, and 60 MPH for most of the I-440 beltline. I can't be 100% certain about this, but I believe the lowest speed limit I've ever seen on an Interstate Highway (other than in a construction zone) was 50 MPH.