History

• The first speed limit law was established in 1901, when Connecticut adopted a 12-mph limit in cities and 15 mph on country roads. The speed limit is generally the responsibility of each particular state or locale. It is usually decided according to a variety of factors, including whether the highway is in an urban area, a non-interstate limited access road, or another type of road. Many cities and highways also employ separate speed limits for passenger vehicles, trucks and larger vehicles.
  
  

Maximum Speed Law

• Congress passed the first maximum-speed bill in 1973, restricting all highways in the country to a 55-mph speed limit. Many states resisted the change, despite mounting concerns over oil and gas availability. In 1987, Congress allowed states increase the speed limit on highways to 65 mph.
  
  

National Highway System Designation Act

• In 1995, the National Highway System Designation Act repealed the maximum-speed law and returned power for setting limits to the individual states. Many states raised speed limits almost immediately, with some rural highways reaching speeds of 80 mph. According to the Cato Institute (cato.org), opponents of the National Highway System Designation Act predicted severe safety problems if the maximum speed was repealed. In fact, fatalities have been reduced since 1974, with average fatalities decreasing even in states raising speed limits since that time.
  
  

Effects of Genetic Drift

• The lowest-recorded figure for road-related injuries occurred in 1997, immediately following the repeal of the national maximum speed law. Despite concerns, this trend of low injury and death rates has continued beyond the 1990s. The increase in speed limit has also resulted in substantial amount of time saved by commuters. One estimate puts the manhours saved in commuting at 300 million hours.