Drag racing is a competition in which specially-prepared automobiles or motorcycles compete two at a time to be the first to cross a set finish line, from a standing start, in a straight line, over a measured distance, most commonly ¼ mile (402 m).
The race track, known as a drag strip, uses an electronic timing system to determine the winner.
Before each race (also known as a pass), each driver is allowed to perform a burnout, which heats the driving tires and lays rubber down at the beginning of the track, improving traction. Each driver then lines up (or stages) at the starting line. Races are started electronically by a system known as a "Christmas tree" . The Christmas tree consists of a column of lights for each driver/lane. In each column, the top two lights are small amber lights connected to light beams on the track, which when broken by the vehicle's front tire(s) indicate that the driver has pre-staged (approximately 7 inches (180 mm) from the starting line) and then staged (at the starting line).
Camaro at launch, with Altered Vision in the right lane. Wheelstan means torque has been wasted lifting the front end, rather than moving the vehicle forward.
Below the staging lights are three large amber lights, a green light, and a red light. When both drivers are staged, the tree is activated to start the race, which causes the three large amber lights to illuminate, followed by the green light. There are two standard light sequences: either the three amber lights flash simultaneously, followed .4 seconds later by the green light (a Pro tree), or the ambers light in sequence from top to bottom, .5 seconds apart, followed .5 seconds later by the green light (a Sportsman tree, or full tree). If the driver breaks the starting line beam before the green light illuminates, the red light for that driver's lane illuminates instead, indicating disqualification (unless a more serious violation occurs). Once a driver commits a red-light foul (also known as ‘redlighting’), the other driver can also commit a foul start by leaving the line too early but still win, having left later.
The winner is the first vehicle to cross the finish line (and therefore the driver with the lowest total reaction time + elapsed time). The elapsed time is a measure of performance only; it does not determine the winner. Because elapsed time does not include reaction time, a car with a faster elapsed time can actually lose.
Several measurements are taken for each race: reaction time, elapsed time, and speed. Reaction time is the period from the green light illuminating to the vehicle leaving the starting line. Elapsed time is the period from the vehicle leaving the starting line to crossing the finish line. Speed is measured through a speed trap 300 feet from the finish line, indicating the approximate maximum speed of the vehicle during the run.
In the standard racing format, the losing car and driver are removed from the contest, while the winner goes on to race other winners, until only one is left
Street racing is a form of unsanctioned and illegalmotor racing which takes place on public roads. Street racing can either be spontaneous or well-planned and coordinated. Well coordinated races are planned in advance and often have people communicating via 2-way radio/citizens' band radio and using police scanners and GPS units to mark locations of local police hot spots.
Evo Street Racers list additional consequences associated with illegal street racing as cruising violations, curfew violations, insurance fraud, warranty fraud, noise complaints, drugs, and vandalism.
Because vehicles used in street racing competitions generally lack professional racing safety equipment such as roll cages and racing fuel cell and drivers seldom wear fire suits and are not usually trained in high-performance driving, injuries and fatalities are common results from accidents. Furthermore, illegal street racers may put ordinary drivers at risk because they race on public roads rather than closed-course, purpose-built facilities, such as Pacific Raceways in the aforementioned city.
Because racing occurs in areas where it is not sanctioned, extensive wear can occur to the roads (from high-powered vehicles damaging the asphalt) and damage to the fences/gates closing the area off (in the case of industrial parks, etc.), this effect is increased by the fact that races often occur on less used roads and as a result, are repaired less often. Further, as the street racing culture places a very high social value on a fast vehicle, people who might not otherwise be able to afford blazingly fast but very expensive vehicles may attempt to steal them, violently or otherwise. Additionally, street racers tend to form teams which participate in racing together, the implication above is that these teams may be a form of organized crime or gang activity