Written by Avvo Staff

Speed limit laws: What you should know

Your guide to understanding speed limit laws and their implications

Speed limit laws are meant to protect motorists, pedestrians, and personal property. The basic rules are simple: if you exceed the posted speed limit, you risk receiving a traffic ticket. However, things aren't always so simple, which is why it helps to be familiar with the laws behind the signs.

Legal speed limits vs. advisory speed limits

You'll notice two different types of posted speed limits on the road.

Legal speed limit signs

These signs feature a white background and black numerals. You must drive at or below this limit if you want to avoid getting a speeding ticket.

If you see a legal speed limit sign on the road, you must reduce your speed to that limit before you pass the sign. Similarly, if the speed limit increases, you can't increase your speed until after you pass the sign.

Advisory speed limit signs

Advisory speed limit signs have a yellow background with black numerals. You might see these signs on curving roads or near bridges. These signs serve as a cautionary notice that road conditions could make it dangerous to travel faster than that speed.

Since the advisory limit is a suggestion, you typically can't get a ticket just for going over it. However, if you crash or cause a collision while exceeding the advisory limit, you may get a careless driving ticket. This is especially true if a police officer determines that your speed contributed to the accident.

The 3 types of speed limit laws

Aside from the signs themselves, the US uses three different types of speed limit laws. The type of law can vary not only by state, but also by road. You may need an attorney to help you figure out which speed limit law applies to your situation.

Absolute speed limits

An absolute speed limit means that the speed limit on the posted sign is the fastest speed you can lawfully travel in any situation. If you're traveling 61 mph in a 60 mph zone, you could receive a ticket for speeding. The police don't have to consider the circumstances to issue a ticket for an absolute speed limit violation.

Presumed speed limits

Presumed speed limit laws make the legal speed limit slightly less concrete. In states that use presumed speed limits, motorists can exceed the posted speed limit if they don't put themselves or anyone else at risk. For instance, light traffic and ideal weather might allow you to speed without violating speed limit laws.

However, presumed speed limits are highly subjective. An officer can still issue you a ticket, which means you must either pay the fine or defend your actions in court.

Basic speed limits

Some states use basic speed limit laws, which state that all drivers have to keep their speed in line with road conditions. In other words, you can get a ticket for speeding even if you're traveling under the legal speed limit. Several different types of hazardous road conditions can impact driver safety and contribute to accidents, such as:

  • Rain
  • Fog
  • Ice
  • Snow
  • Work zones
  • Poorly maintained roads

Basic speed limits usually come into play after an accident. The officers who respond to the scene might issue tickets if they find that one or more drivers traveled too fast for road conditions and could have avoided the accident by reducing speed.

If you receive a ticket for violating basic speed laws, you can always try to get the ticket rescinded in court.

According to Illinois traffic ticket lawyer Jason Alan Wilkins, simply challenging the ticket may be all you need to do. "Ordinarily, these tickets are avoided by the inability of the state to proceed to trial because no witness is available to testify," he says.

In other words, if no one saw the excessive speed, then the state can't prove its case. However, if a pedestrian or other motorist saw the accident, this advantage wouldn't apply.

Knowing how speed limit laws work in your state can help you stay safe on the road and avoid a speeding ticket. But if you do receive a ticket, consider hiring a traffic ticket lawyer to defend you in court.

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