There are three types of speed limits used across the U.S., known as absolute, presumed, and basic. If you have been cited for a speeding violation, you should determine which type of rule you have allegedly violated. This will affect the arguments that you can raise against the ticket and your likelihood of success.
An absolute speed limit is the norm in most states. This involves posting a sign with a certain speed on it and ticketing a driver who exceeds that speed. While many drivers will tell you that an officer will not stop you for driving a few miles over the speed limit, they have a legal right to stop you for driving even one mile over it if they choose. Fighting this type of ticket can be challenging, but you may be able to argue that the officer incorrectly measured your speed or mistook your vehicle for a different vehicle. A driver also may have a defense if they exceeded the speed limit in an emergency to avoid causing serious harm to the driver or others.
Presumed Speed Limits
A presumed speed limit allows a driver to drive slightly faster than the posted limit in optimal conditions. A violation based on a presumed speed limit means that the driver was driving too fast for the conditions. You can argue that you were not exceeding the posted limit if this is true, or you can argue that you were driving safely under the circumstances, even if you were technically exceeding the posted limit. If you were not greatly exceeding the limit, traffic was relatively mild, and the weather was good, this may be a winning argument. If you were driving much faster than the limit, you probably will not prevail.
If they were exceeding the posted limit, the driver has the burden of showing that they were driving safely. You can present photos and diagrams of the scene to show road, weather, and traffic conditions. Also, you can argue that you were keeping up with the speed of traffic around you, and driving more slowly would have created a hazard.
Basic Speed Limits
In some circumstances, it may not be safe to drive at or near the posted speed limit. For example, if traffic is heavy, the road has several curves, and it is snowing, an officer may ticket you for driving too fast even if you were not exceeding the posted limit. This is known as the basic speed limit: a limit defined by a reasonable understanding of what is safe, which is the purpose of having a speed limit.
The prosecution has the burden of proof in this situation to show that your specific speed was too fast to be safe. They need to overcome the presumption created by the posted speed limit that a certain speed on a certain road is safe. Sometimes a state will refer to this violation as driving too fast for conditions. It arises most often in the aftermath of an accident, when an officer may attribute the accident to excessive speed. If there is no accident or near-accident, it may be hard for an officer to show that a speed was unsafe.
You may have grounds to defend against an officer who jumps to the conclusion that you violated the basic speed limit because you were involved in an accident. Another driver may have caused the accident, or it may have resulted from a malfunction in a vehicle, among other causes. An accident even may have resulted from a random event that you could not have anticipated, such as a rotting tree limb falling on your car.