Speed limits on road traffic, as used in most countries, set the legal maximum speed at which vehicles may travel on a given stretch of road. Speed limits are generally indicated on a traffic sign reflecting the maximum permitted speed, expressed as kilometres per hour (km/h) or miles per hour (mph) or both. Speed limits are commonly set by the legislative bodies of national or provincial governments and enforced by national or regional police and judicial authorities. Speed limits may also be variable, or in some places nonexistent, such as on most of the Autobahnen in Germany.
Closed-circuit television (CCTV), also known as video surveillance, is the use of closed-circuit television cameras to transmit a signal to a specific place, on a limited set of monitors. It differs from broadcast television in that the signal is not openly transmitted, though it may employ point-to-point, point-to-multipoint (P2MP), or mesh wired or wireless links. Even though almost all video cameras fit this definition, the term is most often applied to those used for surveillance in areas that require additional security or ongoing monitoring.
A traffic enforcement camera is a camera which may be mounted beside or over a road or installed in an enforcement vehicle to detect motoring offenses, including speeding, vehicles going through a red traffic light, vehicles going through a toll booth without paying, unauthorized use of a bus lane, or for recording vehicles inside a congestion charge area. It may be linked to an automated ticketing system.
Film speed is the measure of a photographic film's sensitivity to light, determined by sensitometry and measured on various numerical scales, the most recent being the ISO system introduced in 1974. A closely related system, also known as ISO, is used to describe the relationship between exposure and output image lightness in digital cameras. Prior to ISO, the most common systems were ASA in the U.S. and DIN in Europe.
DX encoding is an ANSI and I3A standard, originally introduced by Kodak in March 1983, for marking 135 and APS photographic film and film cartridges. It consists of several parts, a latent image DX film edge barcode on the film below the sprocket holes, a code on the cartridge used by automatic cameras, and a barcode on the cartridge read by photo-finishing machines.
Traffic signs or road signs are signs erected at the side of or above roads to give instructions or provide information to road users. The earliest signs were simple wooden or stone milestones. Later, signs with directional arms were introduced, for example the fingerposts in the United Kingdom and their wooden counterparts in Saxony.
A speedometer or speed meter is a gauge that measures and displays the instantaneous speed of a vehicle. Now universally fitted to motor vehicles, they started to be available as options in the early 20th century, and as standard equipment from about 1910 onwards. Other vehicles may use devices analogous to the speedometer with different means of sensing speed, eg. boats use a pit log, while aircraft use an airspeed indicator.
Gatso is the brand that Gatsometer BV use on their speed cameras and red light cameras. The most commonly encountered Gatso speed cameras emit radar beams to measure the speed of a passing vehicle. If it is travelling above the preset trigger speed, one or two photographs are taken. These use a powerful flash, to show the rear of the vehicle, its registration plate, and calibration lines on the road. Newer installations used digital cameras which have limited exposure latitude compared to film, these installations use an auxiliary flash placed close to the position where a speeding vehicle would exit the radar beam and the first photograph would be taken.
Advanced driver-assistance systems (ADAS) are technologies that assist drivers with the safe operation of a vehicle. Through a human-machine interface, ADAS increase car and road safety. ADAS use automated technology, such as sensors and cameras, to detect nearby obstacles or driver errors, and respond accordingly. ADAS can enable various levels of autonomous driving.
A red light camera is a type of traffic enforcement camera that photographs a vehicle that has entered an intersection after the traffic signal controlling the intersection has turned red. By automatically photographing vehicles that run red lights, the photo is evidence that assists authorities in their enforcement of traffic laws. Generally the camera is triggered when a vehicle enters the intersection after the traffic signal has turned red.
Automatic number-plate recognition is a technology that uses optical character recognition on images to read vehicle registration plates to create vehicle location data. It can use existing closed-circuit television, road-rule enforcement cameras, or cameras specifically designed for the task. ANPR is used by police forces around the world for law enforcement purposes, including checking if a vehicle is registered or licensed. It is also used for electronic toll collection on pay-per-use roads and as a method of cataloguing the movements of traffic, for example by highways agencies.
Clearview, also known as Clearview Hwy, is the name of a humanist sans-serif typeface family for guide signs used on roads in the United States, Canada, Indonesia, the Philippines, Israel, Brazil and Sri Lanka. It was developed by independent researchers with the help of the Texas Transportation Institute and the Pennsylvania Transportation Institute, under the supervision of the Federal Highway Administration (FHWA). It was once expected to replace the FHWA typefaces in many applications, although newer studies of its effectiveness have called its benefits into question.
In the United States, speed limits are set by each state or territory. States have also allowed counties and municipalities to enact typically lower limits. Highway speed limits can range from an urban low of 25 mph (40 km/h) to a rural high of 85 mph (137 km/h). Speed limits are typically posted in increments of five miles per hour (8 km/h). Some states have lower limits for trucks, some also have night and/or minimum speed limits.
Automotive tires are described by an alphanumeric tire code or tyre code, which is generally molded into the sidewall of the tire. This code specifies the dimensions of the tire, and some of its key limitations, such as load-bearing ability, and maximum speed. Sometimes the inner sidewall contains information not included on the outer sidewall, and vice versa.
Malaysian Federal Roads System, is the main national road network in Malaysia. All Federal Roads in Malaysia are under the purview of the Ministry of Works (MOW). According to the Ministerial Functions Act 1969, the MOW is responsible to plan, build and maintain all Federal Roads gazetted under the Federal Roads Act 1959. However, most of the Federal roads' projects were built and maintained by the Malaysian Public Works Department (JKR), which is also one of the implementing agencies under the MOW.
SPECS is an average speed measuring speed camera system introduced in 1999. It is one of the systems used for speed limit enforcement in the United Kingdom.
d-cam is a type of digital speed camera produced by the British subsidiary of the South African company Truvelo Manufacturers (Pty) Ltd. Testing by Transport for London commenced on the A4 Great West Road in London, in April 2007. The camera does not flash and can be used rear or forward-facing. It was the first combined traffic light camera and speed camera to be used in the United Kingdom. The new style of camera housing was designed by Bristol-based firm Crown (UK) Ltd.
A collision avoidance system (CAS), also known as a pre-crash system, forward collision warning system (FCW), or collision mitigation system, is an advanced driver-assistance system designed to prevent or reduce the severity of a collision. In its basic form, a forward collision warning system monitors a vehicle's speed, the speed of the vehicle in front of it, and the distance between the vehicles, so that it can provide a warning to the driver if the vehicles get too close, potentially helping to avoid a crash. Various technologies and sensors that are used include radar (all-weather) and sometimes laser (LIDAR) and cameras to detect an imminent crash. GPS sensors can detect fixed dangers such as approaching stop signs through a location database. Pedestrian detection can also be a feature of these types of systems.
Speed limits are enforced on most public roadways by authorities, with the purpose to improve driver compliance with speed limits. Methods used include roadside speed traps set up and operated by the police and automated roadside 'speed camera' systems, which may incorporate the use of an automatic number plate recognition system. Traditionally, police officers used stopwatches to measure the time taken for a vehicle to cover a known distance. More recently, radar guns and automated in-vehicle systems have come into use.
Road speed limit enforcement in the United Kingdom is the action taken by appropriately empowered authorities to attempt to persuade road vehicle users to comply with the speed limits in force on the UK's roads. Methods used include those for detection and prosecution of contraventions such as roadside fixed speed cameras, average speed cameras, and police-operated LIDAR speed guns or older radar speed guns. Vehicle activated signs and Community Speed Watch schemes are used to encourage compliance. Some classes of vehicles are fitted with speed limiters and intelligent speed adaptation is being trialled in some places on a voluntary basis.
