Maximum Speed Limits in the US by State
Speed limits refer to the maximum speed a vehicle can legally travel on a particular road. These limits are typically indicated on a road sign and expressed in miles per hour or kilometers per hour. Currently, every state or territory in the United States determines its speed limit. Municipalities and counties within states are also allowed to set their speed limits. The purpose of these limits is to protect road users from accidents and discourage dangerous driving. Although there’s no guarantee that speed limit signs can modify driver behaviors, enforcing the limits by punishing offending drivers can assist in building a safer driving environment.
History of Speed Limits in the United States
In 1973, the Organization of Arab Petroleum Exporting Countries (OPEC) placed an oil embargo on the United States and other countries that supported Israel in the Yom Kippur War, effectively increasing oil prices. To reduce oil consumption across the country, Congress enacted the 1974 Emergency Highway Energy Conservation Act and created the National Maximum Speed Law that set the federal 55 miles per hour speed (mph) limit. Although the federal government withheld project funding for states with speed limits higher than 55 mph, motorists nationwide disregarded the law, and some states openly opposed it. Eventually, the law was repealed in 1995 by the National Highway System Designation Act, returning the power to enact speed limit laws back to the individual states.
Speed Limits by State 2022
Speed limits are designed to reflect the speed at which over 80% of drivers would comfortably drive without posted limits. It is determined by several factors, including the road category, the flow of traffic, physical conditions of the road, the presence of schools, etc. Some roads in states like Montana have different speed limits for day and night, while states like Idaho, Michigan, and California have varying limits for cars and trucks.
Roads in the United States are divided into three main categories–Arterial roadways, Collector Roadways, and Local Roadways. Arterial roads, such as interstates, provide the highest mobility level and deliver high traffic volumes from collector roads to expressways. They typically have fewer access points and can sustain higher speeds. Therefore, interstate speed limits by state are usually the highest among other roads. Collector roads like county roads are low-to-moderate capacity roads that deliver traffic from arterial roads to local roads. These roads have more access points and lower speed limits than their arterial counterparts. Local roads have the highest number of access points and the lowest speed limits. Examples of such roads include neighborhood streets and intersections.
The Texas State Highway 130 currently holds the record for the highest speed limit in USA. The toll road, which runs from Austin to San Antonio and bypasses the Austin metropolitan area for long-distance traffic, has an 85 mph speed limit. On the other hand, the country’s lowest maximum speed limit is 30 mph and can be found in American Samoa. Generally, highway speed limits in the country range from 70-80 mph on the West Coast, inland eastern, and inland western states to as low as 55-60 mph in Hawaii.
If you're wondering, "what's the speed limit in my state?," the table below answers your question by showing the state speed limits in the United States:
|State or Territory||Rural Interstates (mph)||Urban Interstates (mph)||Other limited access roads (mph)||Residential roads (mph)|
|Arkansas||70–75 (cars) 70 (trucks)||65||45–65||20–30|
|California||65–70 (cars) 55 (trucks)||50–65||55–65||25–30|
|District of Columbia||N/A||N/A||N/A||25|
|Indiana||70 (cars) 65 (trucks)||50–70||50–55||20–30|
|Montana||75–80 (cars) 70 (trucks)||65||55–70||20–25|
|Northern Mariana Islands||N/A||N/A||45||25|
|Oregon||65–70 (cars) 60–65 (trucks)||50–60||55–70||20–25|
|Puerto Rico||60–65 (cars) 55 (trucks)||50–55||45–55||25–35|
|US Virgin Islands||N/A||N/A||30–40||20–25|
|Washington||70 (cars) 60 (trucks)||60||55–65||20–50|
IIHS-HLDI crash testing and highway safety
Some organizations, such as the Insurance Institute for Highway Safety (IIHS) and the Highway Loss Data Institute (HLDI) take a scientific approach to preventing road accidents and lowering human and property loss from vehicle crashes. IIHS is an independent, non-profit scientific body funded by auto-insurers. This organization serves to reduce deaths, injuries, and property damage from automobile accidents through research and education of stakeholders, consumers, and safety professionals. HLDI assists the IIHS in achieving its purpose by publishing scientific studies of insurance data depicting human and property losses by vehicle make and model. Together, these organizations conduct crash testing and highway safety tests on vehicles to determine their crashworthiness (how well they protect their occupants in a crash) and the effectiveness of their crash avoidance and mitigation technology.