(Updated 5/22/20)
Motor vehicle laws, including speed limits, in the United States are not federally mandated. 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.
Not all states are created equal when it comes to their traffic laws. While all states aim to create laws to protect their drivers, some are much more restrictive than others, and a select few take traffic restrictions, particularly those related to speeding, to an extreme. For example, 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.*
*Update: this law has not passed and the highest speed you can legally go in Missouri is 70 MPH.
Interestingly, as you travel west from Missouri, into Kansas, Oklahoma, or Nebraska, the speed limit on rural roads is 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.
Speeding Limit Laws Across The United States
A few of the more mild examples of this can be found in Pennsylvania and New York. Exceeding the speed limit by 11 mph or more will get you a mandatory 15-day license suspension in Pennsylvania, and could get you up to 15 days in jail in New York. Minnesota also boasts an extreme punishment for extreme speeders, allowing for a 6-month license suspension for exceeding 100 mph anywhere in the state.
Wisconsin allows for the addition of six points to your license if you’re caught doing more than 20 mph over the speed limit. This is the same number of points you would receive for a first-offense DUI in this state. They’ll also add on a 15-day license suspension if you exceed the speed limit by 25 mph or more in a 55 of 65 mph zone.
Virginia is by far the worst state to be caught speeding in. Their extreme speeding laws recently gained national attention after a well-known auto reviewer was caught speeding while on a press drive for the new Camaro ZL1. He wrote an article on his experience, explaining how he was caught doing 93 in a 55 mph zone and, despite the best efforts of his lawyer, had to return to the state to spend a weekend in jail because he was charged with reckless driving in addition to speeding. There are a number of ways an officer can add a reckless driving charge to a speeding ticket in Virginia, from the obvious offenses, like excessive speeding, to something as trivial as failure to use a turn signal. This bumps a speeding charge up to a misdemeanor (or a felony if it’s your second offense within three years) and automatically adds $950 to $3000 and jail time to your sentence.
Not all states are out to get drivers, though. Georgia stands out as the most driver-friendly state, with no fine if you are speeding by less than five miles per hour over the limit, and no points on your license if you’re found to be driving too fast for conditions.