Q. State Speed Limit Laws
The maximum posted speed limit listed by state, for trucks as well as cars, is available from the Insurance Institute for Highway Safety at: http://www.iihs.org/laws/speedlimits.aspx
You can access the Insurance Institute for Highway Safety home page at: http://www.iihs.org
(Note: The above private-sector site is not maintained by USDOT or any other US Government office. We take no responsibility for the content or accuracy of any non-USDOT web page, and offer the above link strictly as a courtesy, should you be interested.)
For information on state speed limits and sanctions, see the National Highway Traffic Safety Administration's "Summary of State Speed Laws (2010)" at http://www.nhtsa.gov/staticfiles/nti/pdf/811457.pdf
You may also want to contact DOT at the state level for this information.
Links to state Departments of Transportation and/or state government web sites are available on: http://www.fhwa.dot.gov/webstate.htm