Speed Limits: History, Types & Speed Limit by State

Love them or hate them, speed limits are everywhere and an important part of safe driving. With speed limits posted on signs on almost every street and interstate highway around the country, we’re dedicating time to look at them closely. How did we get speed limits? Why do they vary so much on highways from state to state? Have they changed over the years? Keep reading to learn all of this and more!

History of Speed Limits

According to the American Safety Council, speed limits date all the way back to 1901 when Connecticut set a maximum speed for motor vehicles. The results of the legislation? Drivers were limited to 12 miles per hour inside city limits and 15 miles per hour on rural roads. As the years passed, cars were able to move at higher speeds, and speed limits were adjusted to match scientific advancements. Today, speed limits are in every state, and they continue to evolve as both vehicles and roads become safer.

How are Speed Limits Established?

Wondering how speed limits are set? You’re not alone! The numbers you are used to seeing are actually the result of in-depth studies conducted by state and local transportation agencies. These studies consider a number of factors, including, but not limited to:

Roadway type and setting
Visibility
Roadway features, like curves and hills
Crash history on the road
Pedestrian and cyclist traffic
Lane and shoulder width

By weighing all these factors and many more, experts can determine how fast people can drive while remaining safe.

Different Types of Speed Limits

When it comes to speed limits, most drivers believe they just have to stay under the indicated number, and they’ll be okay. However, speed limit laws are more than that, as noted here by the Federal Highway Administration. Speed limits set the legal maximum and legal minimum speed at which vehicles may travel on a given stretch of road. Let’s look at different types of speed limits.

Statutory Speed Limits vs Posted Speed Limits

Oftentimes, state legislatures have set speed limits for different types of roads. Lawmakers might determine that all interstates should generally have a speed limit of 70 miles per hour that drops to 60 miles per hour around large cities. These numbers, statutory speed limits, act as a starting point or base, and they can be enforced even if there’s no posted number along the road.

Meanwhile, posted speed limits are exactly what they sound like. These are the bold, black numbers you see painted on the white, rectangular signs on the side of a road. A posted speed limit might be the same as a statutory speed limit, but it could also vary. If a particularly curvy stretch of remote highway is deemed to be dangerous, it might have a lower speed limit than other rural highways around the state.

Basic Speed Limits vs Absolute Speed Limits

Anyone who has driven a car has seen a speed limit sign, and it’s a pretty simple concept to understand. If you drive over the number posted, you’re in danger of receiving a speeding ticket. However, this is just one type of speed limit, known as an absolute speed limit. In other words, that is the absolute fastest you can legally drive on that particular roadway.

Another type of speed limit law that many people are unaware of is a basic speed limit, which is situational depending on driving conditions. If you look at your state’s laws, you might find something along the lines of this California statute:

“No person shall drive a vehicle upon a highway at a speed greater than is reasonable or prudent having due regard for weather, visibility, the traffic on, and the surface and width of, the highway, and in no event at a speed which endangers the safety of persons or property.”

As you can probably tell from the description above, basic speed laws exist to protect people as driving conditions change. For example, if you’re driving 70 miles per hour (the posted limit) on a crowded interstate in the middle of a snowstorm, that could be considered unsafe given the circumstances.

You might also have heard of a presumed speed limit. If you drive over a presumed speed limit, you have the chance to make the case that the speed you were driving was actually safe considering the circumstance (like a lack of traffic and good visibility). However, this leaves a lot to chance and can be risky because you can’t assume you’ll beat the presumption that you were speeding.

Minimum Speed Limits

Pretty much every driver is aware that they can’t drive above a certain speed without risking an expensive traffic ticket. But did you know that you might not be allowed to drive under a certain speed? Minimum speed limits also exist to make sure drivers stay safe, but in this case, it’s to keep people from driving slower than expected. Why is driving slowly a bad idea? Wouldn’t that mean the driver is being careful? Not necessarily. If weather conditions are perfect and visibility is clear, driving 35 miles per hour on an uncrowded interstate would be an unexpected safety hazard for other cars. You can also find yourself in trouble if you’re driving too slow in the left lane, which is why you might see signs telling slower traffic to keep to the right.

Move Over, Slow Down Law

‘Move Over’ laws are fairly new additions to the law books of states in the US, with the first law passed in South Carolina in 2002, and 49 states following suit.

Often summarized as “move over, slow down,” these laws direct a motorist who notices an emergency vehicle on the road to move one lane over to give the vehicle clearance or slow down significantly to avoid an accident. This includes law enforcement vehicles, fire trucks, ambulances, and in some cases, tow-truck drivers and disabled vehicle. Every state has its own variation of the law.

What is the move over law speed limit?

Each state sets its provisions related to a driver's responsibility to reduce speeds. When approaching an emergency vehicle with lights flashing, drivers should slow down to a safe speed and cautiously approach. If possible or if the state requires it, drivers should move over into an adjacent lane, such as on multi-lane roadways. Some states recommend slowing to a speed 10-20 mph less than the posted speed limit.

If you violate your state’s move over or slow down law, you may have committed a serious offense—the kind that could get your license suspended or possibly revoked. You might also need to file an SR-22 before you can get behind the wheel again, so it pays to know what the law is where you live!

Other Types of Speed Limits

According to the Federal Highway Administration, some speed limits are determined on a conditional basis. For example, school zones and construction zones have special speed limits to protect drivers, pedestrians, and workers. Also, some roadways feature variable speed limit signs that can change depending on factors like weather. Finally, advisory speed limits are seen on specific parts of a roadway, like large curves.

Recapping Different Types of Speed Limits

In summary, speed limits are designed to keep us safe and there a number of different kinds:

Statutory speed limits are general guidelines for certain types of roads while posted speed limits are the actual numbers you see on signs.
Absolute speed limits are the numbers posted on signs indicating the maximum speed you can drive, whereas basic speed limits are situational depending on driving conditions.
Minimum speed limits exist so that people don’t drive too slow and put faster-moving vehicles in danger.
Conditional speed limits are used in certain areas, like construction zones or school zones.
Variable speed limits change depending on traffic and conditions.
Advisory speed limits give drivers guidance on potentially hazardous stretches of road, like large curves or those with a lot of wildlife.

Do Speed Limits Vary from State to State?

If you’ve been driving for a while, you’re probably accustomed to seeing speed limits fluctuate from state to state. Without changing roads, you may be able to speed up or be forced to slow down when you cross a state line. Has this always been the case? Why do speeds fluctuate so much?

Has it always been this way?

Throughout U.S. history, states have been responsible for setting their speed limits. However, this changed in the 1970s when Richard Nixon signed a bill into law that made the national speed limit 55 miles per hour. Fuel had become more expensive due to conflict in the Middle East, and Nixon hoped this measure would force people to drive at a more fuel-efficient speed. National speed limit laws lasted for about 20 years with Congress returning speed limit decisions to individual states in 1995.

Why do speed limits vary in different states?

Lawmakers in one state may view 80 miles per hour as a reasonable speed, but lawmakers in a neighboring state might see 70 miles per hour as more reasonable. There are a number of reasons why different conclusions are drawn, but ultimately it comes down to safety. Every state’s officials have to determine what they believe is safe for their residents, and due to different factors (like geography), limits vary. For example, a rural highway in West Texas probably has less traffic and offers more visibility than what’s considered a rural highway in many other states. So a safe speed in West Texas might be higher than what’s regarded as a safe speed in a neighboring state.

Speed Limit by State

Wondering how fast you can drive in your state? We’ve got you covered! This is how fast you can drive on different types of roads in each state, according to the Governors Highway Safety Association. While these are all general guidelines, please note there may be exceptions. Always check every road for posted speed limits!

State	Speed Limit on Rural Interstates (MPH)	Speed Limit on Urban Interstates (MPH)	Speed Limit on Other Limited Access Roads (MPH)
Alabama	70	65	65
Alaska	55	55	55
Arizona	75	65	65
Arkansas	75 (70 for trucks)	65 (60 on specified limits)	75
California	70 (55 for trucks)	65 (55 for trucks)	70 (55 for trucks)
Colorado	75	65	65
Connecticut	65	55	65
Delaware	65	55	65
District of Columbia	N/A	55	N/A
Florida	70	65	70
Georgia	70	70	65
Hawaii	60	60	55
Idaho	75; 80 on certain segments (70 for trucks)	75; 80 on certain segments (65 for trucks)	70
Illinois	70	55	65 (55 for trucks)
Indiana	70 (65 for trucks)	55	60
Iowa	70	55	70
Kansas	75	75	75
Kentucky	65; 70 on certain segments	65	65
Louisiana	75	70	70
Maine	75	75	75
Maryland	70	70	70
Massachusetts	65	65	65
Michigan	70; 75 on certain segments (65 for trucks)	70 (60 for trucks; 55 for trucks if the speed limit for cars is less than 70)	70 (60 for trucks; 55 for trucks if the speed limit for cars is less than 70)
Minnesota	70	65	65
Mississippi	70	70	70
Missouri	70	60	70
Montana	80 (70 for trucks)	65	70 during day; 65 at night (60 during day for heavy trucks; 55 at night for heavy trucks)
Nebraska	75	70	70
Nevada	80	65	70
New Hampshire	65; 70 on certain segments	65; 70 on certain segments	55; 70 on certain segments
New Jersey	65	55	65
New Mexico	75	75	65
New York	65	55	55
North Carolina	70	70	70
North Dakota	75	75	70 on 4-lane roads; 65 on other roads
Ohio	70	65	70
Oklahoma	75	70	70
Oregon	65; 70 for cars on certain segments	55	65
Pennsylvania	70	70	70
Rhode Island	65	55	55
South Carolina	70	70; 60 on certain segments	60
South Dakota	80	80	70
Tennessee	70	70	65
Texas	75; 80 or 85 on certain segments	75	75
Utah	75; 80 on certain segments	65; 70 on certain segments	75
Vermont	65	55	50
Virginia	70	70	65
Washington	70 (60 for trucks)	60	60
West Virginia	70	60 or 65	65
Wisconsin	70	70	70
Wyoming	75; 80 on certain segments	75, 80 on certain segments	65; 70 on certain segments

No matter what the speed limit is where you plan to drive, you’re going to need car insurance you can count on, so why not choose Direct Auto? Give us a call at 877-463-4732, visit our website and get a free online quote, or visit a nearby Direct Auto location for a free quote!

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