Traffic on roads may consist of pedestrians, ridden or herded animals, vehicles, streetcars and other conveyances, either singly or together, while using the public way for purposes of travel. Traffic laws are the laws which govern traffic and regulate vehicles, while rules of the road are both the laws and the informal rules that may have developed over time to facilitate the orderly and timely flow of traffic.
Organized traffic generally has well-established priorities, lanes, right-of-way, and traffic control at intersections.
Emergency vehicle lighting is visual warning lights fitted to a vehicle for use when the driver wishes to convey to other road users the urgency of their journey, to provide additional warning of a hazard when stationary, or in the case of law enforcement as a means of signalling another driver to stop for interaction with an officer. These lights may be dedicated emergency lights, such as a beacon or a light bar, or may be modified stock lighting, such as a wig-wag or hide-away light, and are additional to any standard lighting on the car such as hazard lights. Often, they are used along with a siren (or occasionally sirens) in order to increase their effectiveness. In many jurisdictions, the use of these lights may afford the user specific legal powers, and may place requirements on other road users to behave differently, such as compelling them to pull to the side of the road and yield right of way so the emergency vehicle may proceed through unimpeded.
Laws regarding and restricting the use of these lights vary widely between jurisdictions, and in some areas non-emergency vehicles (e.g. school buses) and semi-emergency vehicles (e.g. tow trucks) may be permitted to use similar lights. These non-and semi-emergency lights are also discussed here. Research into the usefulness and potential dangers of these lights is also presented.
The lighting system of a motor vehicle consists of lighting and signalling devices mounted or integrated to the front, sides, rear, and in some cases the top of the motor vehicle. The purpose of this system is to provide illumination for the driver to operate the vehicle safely after dark, to increase the conspicuity of the vehicle, and to display information about the vehicle's presence, position, size, direction of travel, and driver's intentions regarding direction and speed of travel.
The term crime does not, in modern times, have any simple and universally accepted definition, but one definition is that a crime, also called an offence or a criminal offence, is an act harmful not only to some individual, but also to the community or the state (a public wrong). Such acts are forbidden and punishable by law.
A social issue (also called a social problem or a social situation) is an issue that relates to society's perception of a person's personal lives. Different cultures have different perceptions and what may be "normal" behavior in one society may be a significant social issue in another society. Social issues are distinguished from economic issues. Some issues have both social and economic aspects, such as immigration. There are also issues that don't fall into either category, such as wars.
Thomas Paine, in Rights of Man and Common Sense, addresses man's duty to "allow the same rights to others as we allow ourselves". The failure to do so causes the birth of a social issue.