A wheel clamp is a locking device, sometimes known as a "boot," used to keep a vehicle from being moved. This device typically clamps around the wheel of a vehicle and cannot be removed without the use of a key or combination code. Although a wheel clamp can be used to prevent the theft of a vehicle, it is primarily used by private property owners and police to discourage unauthorized parking. In the U.S., this device was first used by the Denver, Colorado, police department to help reduce the expense of towing and impounding illegally parked vehicles. Wheel clamps are also used by some local governments to assist in the collection of unpaid parking fines.
Originally referred to as an auto immobilizer, the wheel clamp has been in use since the 1950s. The device was invented in the 1940s by Frank Marugg, a Denver Symphony Orchestra violinist. Marugg was acquainted with a Denver police officer who thought his invention might be useful to the police department. When the device began to be used by the department for illegally parked vehicles, it became known as the Denver boot. The Denver police department’s use of the wheel clamp was so successful that $18,000 (USD) in traffic fines was collected during its first month of use.
When a wheel clamp is attached to a vehicle’s wheel, neither the clamp nor the wheel can be removed without assistance. Owners of illegally parked vehicles are often forced to pay outstanding traffic fines in order to have their vehicle released from the clamp. Property owners typically charge a clamp removal fee hoping that it will prevent future parking violations from occurring. Wheel clamp removal fees for private property parking violations may or may not be subject to local government regulations and can sometimes become very expensive.
Some police departments and municipal parking authorities use a type of self-service wheel clamp to further reduce the time and expenses associated with illegal parking. Clamps utilizing a special combination code locking mechanism are attached to illegally parked vehicles and the owners must call and give their credit card number to receive unlocking instructions. Once removed, the clamp must then be attached to a nearby street lamp for pick up. If the clamp is not found by the police, the vehicle owner’s credit card will be charged for the cost of the missing clamp as well.
Many property owners hire a private company to clamp the wheel of an illegally parked vehicle and collect the removal fees. In areas where wheel clamping is in widespread use, vehicle owners have been known to remove clamps using bolt cutters and angle grinders. Some vehicle owners purchase their own clamp and attach it to their vehicle to prevent it from being clamped by a property owner. In recent years, wheel clamping on private property has been outlawed in the U.S. state of Washington and the country of Scotland.