The use of cameras to enforce traffic laws isn't new. The two most common applications — speed cameras and red light cameras — have been used for years in Canada, Australia, and a number of countries in Europe. Automated enforcement is common in these countries, and it's becoming more sophisticated as technology progresses. New applications are continually being tested.
Police have turned to technology because traditional enforcement alone isn't enough to curb violations. There are only so many officers on patrol. Even on dedicated patrols, each officer is likely to observe and ticket only a handful of violators. The main limitation of traditional enforcement is thus manpower. Drivers know the risk of being detected is small.
This is where cameras come in. They can be placed in many locations to operate around the clock and identify virtually every offender. The deterrent effect is obvious — drivers are discouraged from violating the laws because they know the risk of detection goes up when cameras are in use.
"The goal of automated enforcement, with its huge capacity, is to significantly increase the objective and perceived chances of being caught, thus creating a change in behavior that will translate into a crash reduction, whether it applies to speeding, running red lights, or tailgating," says Shalom Hakkert, a visiting Institute scholar who has been studying automated enforcement practices around the world.
Also called photo radar, speed cameras are the most widely used form of automated enforcement in the world. They're in Australia, Austria, Israel, the Netherlands, Norway, and the United Kingdom. Between tens and hundreds of sites in each country have speed cameras.
The cameras aren't functioning as a small adjunct to traditional police enforcement. They're generating the majority of all speeding tickets in some countries. For example, in the United Kingdom almost half of all speeding tickets result from automated enforcement. In contrast, photo radar has never been used extensively in the United States. It's being tried now in a few communities including Washington, D.C., and early results indicate fewer speeders. However, such programs are exceptions.
Two camera types are in use. One takes single "spot" measurements of vehicle speeds, using either radar or cables buried in the roadway to measure the speeds. When a speeding vehicle is detected, a camera snaps two photos of the license plate, typically the rear plate. Another type of camera system measures average vehicle speeds over given distances.
"The rationale for taking an average is essentially to give a driver the benefit of the doubt," Hakkert says. "It avoids the complaint that sometimes arises with ordinary speed cameras, which is that a single spot measurement could somehow be unfair."
The Netherlands is testing a system that uses sets of three speed cameras installed over a three-kilometer stretch of highway. Vehicles are digitally photographed as they pass below each camera. The images are stored only long enough to enable the system to search for matches. When a match is found, the vehicle's average speed is calculated, and if it exceeds the limit the images of that particular vehicle and license plate are stored as evidence of a violation.
Red light cameras
Like speed cameras, red light cameras are in use around the world including Australia, Canada, many European countries, Israel, Singapore, South Africa, and Taiwan. In the United States, at least eight major cities and a number of smaller communities use red light cameras. However, the extent of use in U.S. communities doesn't approach the use being made of red light cameras in Australia, for example, where their use dates back to 1981. In the Melbourne area alone, 35 red light cameras are being rotated among 132 sites.
The basic technology has been around since the 1960s. Cameras are set up to photograph vehicles that enter intersections after signals have turned red. Detection of an offense is made by sensors that are buried in the pavement and connected to the traffic signals and camera. Some newer systems use video instead of 35 mm film.
One video system can predict red light violations several seconds before they occur. Then the system automatically extends the all-red signal to prevent collisions from occurring.
Automated enforcement isn't limited to speed cameras and red light cameras. In the United States, photo enforcement is being used to monitor illegal railway crossings and violations of laws requiring vehicles to stop for school buses. In the Netherlands and Israel, cameras monitor tailgating.
Multiple application systems are another new development. One currently being tested in London monitors for red light runners and speeders at the same time. Other camera uses include checking for overweight trucks, illegal use of bus and high occupancy traffic lanes, and toll violations.
Future of automation
Most current systems aren't fully automated. Only the detection and recording of offenses is automatic. The ticketing part of the process still is done manually by reviewing the photographic evidence.
Fully automated systems may be in the future. Digital cameras already exist that can recognize license plates, link to motor vehicle registration databases, and issue tickets. The speed enforcement system being tested in the Netherlands has this capability. However, many technical, legal, and political issues will have to be worked out before completely automated enforcement is widely accepted.
Courts in San Diego and elsewhere find no constitutional flaws
Courts in San Diego and elsewhere find no constitutional flaws
Relatively few U.S. jurisdictions use red light cameras or photo radar, compared with other countries. But the numbers are growing, even as a small but outspoken contingent of camera critics complains to the courts that cameras invade privacy or otherwise are unconstitutional.
A highly publicized lawsuit was brought in 2001 in San Diego, California, over the city's use of red light cameras. The Superior Court judge deciding the case issued a ruling that eventually led to the dismissal of about 300 tickets. Camera opponents hailed this as a landmark but, in fact, the judge specifically upheld the constitutionality of the camera program. The tickets were dismissed because of defects in how the program was operated. Specifically, the city was found to be at fault for allowing the contractor excessive control and for paying the contractor according to the number of paid tickets.
Institute senior transportation engineer Richard Retting says "to gain public trust, camera programs must be operated in ways above any suspicion of a profit motive. When a contractor runs a program and gets paid per ticket, that's a flawed business model, especially because the objective should be to deter offenders and, therefore, write no tickets. The good thing about San Diego is that government agencies now have judicial guidance on what to avoid when they set up the administrative aspects of their programs."
Court challenges also have forced changes in Denver, Colorado's camera program, which has been halted while the city reassesses its administration. The city dismissed all outstanding photo radar tickets after a district court judge ruled that the program illegally gave police powers to a private contractor. The policy of compensating a contractor based on ticket volume also was found to violate state law. Retting notes that the flaws were technicalities, "but technicalities are important, and they have to be handled properly if automated law enforcement if going to succeed."