Missouri Speed Limits
Motor vehicle laws, including speed limits, in the United States are not federally mandated. They vary from state to state and the legislature of each state is responsible for making those laws. In Missouri, 70 miles per hour is the fastest you can legally drive, and this is only on freeways in rural areas. When you enter an urban area on those freeways, the limit goes down to 60-65 mph as posted. The limit is 65-70 on rural divided roads, and 55-65 on undivided roads. Residential roads have limits of 35-40 mph unless otherwise posted.
The Missouri statutes regarding speeding start with The Basic Speed Rule: A person shall operate a motor vehicle in a careful and prudent manner and at a rate of speed so as not to endanger the property of another or the life or limb of any person and shall exercise the highest degree of care. (304.010.1) After this, over 100 more statutes just regarding speeding follow. There is a bill just introduced into the legislature to change the limit on rural highways to 75 miles per hour. This would put Missouri in line with the rural limits in Kansas.
Interestingly, as you travel west from Missouri, into Kansas, Oklahoma or Nebraska, the speed limit on rural roads are higher, most set at 75 mph. If you are traveling east, north, or south, you had better slow down as these states (Iowa, Arkansas and Illinois) all have top limits of 65 mph. Only Tennessee and Kentucky match Missouri with 70 mph on rural freeways.