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Operating Speed
The operating speed of a road is the speed at which motor vehicles generally operate on that road. The precise definition of "operating speed", however, is open to debate. Some sources, such as the AASHTO, have changed their definitions recently to match the common use of the word. In 1994, the AASHTO ''Green Book'' defined the operating speed as "the highest overall speed at which a driver can travel on a given highway under favorable weather conditions and under prevailing traffic conditions without at any time exceeding the safe speed as determined by the design speed on a section-by-section basis," a definition which a majority of US states still use. In July 2001, however, the AASHTO revised their definition for the new edition of the ''Green Book'' and defined it as "the speed at which drivers are observed operating their vehicles during free-flow conditions." See also *Assured Clear Distance Ahead *Design speed *Solomon curve *Speed limit *Traffic psychology Traffic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motor Vehicles
A motor vehicle, also known as motorized vehicle or automotive vehicle, is a self-propelled land vehicle, commonly wheeled, that does not operate on Track (rail transport), rails (such as trains or trams) and is used for the transportation of people or cargo. The vehicle propulsion is provided by an engine or motor, usually an internal combustion engine or an electric motor, or some combination of the two, such as hybrid electric vehicles and plug-in hybrids. For legal purpose, motor vehicles are often identified within a number of vehicle classes including cars, buses, motorcycles, off-road vehicles, light trucks and regular trucks. These classifications vary according to the legal codes of each country. International Organization for Standardization, ISO 3833:1977 is the standard for road vehicle types, terms and definitions. Generally, to avoid requiring people with disabilities from having to possess an operator's license to use one, or requiring tags and insurance, powered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Assured Clear Distance Ahead
In legal terminology, the assured clear distance ahead (ACDA) is the distance ahead of any terrestrial locomotive device such as a land vehicle, typically an automobile, or watercraft, within which they should be able to bring the device to a halt. It is one of the most fundamental principles governing ordinary care and the duty of care for all methods of conveyance, and is frequently used to determine if a driver is in proper control and is a nearly universally implicit consideration in vehicular accident liability. The rule is a precautionary trivial burden required to avert the great probable gravity of precious life loss and momentous damage. Satisfying the ACDA rule is necessary but not sufficient to comply with the more generalized basic speed law, and accordingly, it may be used as both a layman's criterion and judicial test for courts to use in determining if a particular speed is negligent, but not to prove it is safe. As a spatial standard of care, it also serves as r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Design Speed
The design speed is a tool used to determine geometric features of a new road or street during road design. Contrary to the word's implication, the design speed of the road or street is not necessarily its vehicle speed limit or maximum safe speed; that can be higher or lower. Choosing a design speed means finding a balance between several interests which compete for priority, such high vehicle speeds to allow driving, drivers to travel to their destinations quickly versus low vehicle speeds for the road traffic safety, safety of people outside the vehicle (such as pedestrians and cyclists), or traffic flow, quick movement of rush hour, peak traffic (Traffic engineering (transportation), traffic engineering) versus maximising the economic development potential of the street (urban planning). Geometric features The design speed chosen for a high-speed roadway is a major factor in choosing cant (road/rail), superelevation rates and radii of road curve, curves, stopping sight di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solomon Curve
] The Solomon curve is a graphical representation of the collision rate of automobiles as a function of their speed compared to the average vehicle speed on the same road. The curve was based on research conducted by David Solomon in the late 1950s and published in 1964. Subsequent research suggests significant biases in the Solomon study, which may cast doubt on its findings. The original research In 1964, Solomon researched the relationship between average speed and the collision rates of automobiles and plotted the results. While others have attempted to quantify the relationship between average speed and collision rates, Solomon's work was both "the earliest and best known". Solomon conducted a comprehensive study of more than 10,000 collision-involved drivers and their vehicles and how other roadway, driver, and vehicle characteristics affect the probability of being involved in a crash. He found that the probability of being involved in a crash per vehicle-mile as a functi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speed Limit
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) and/or miles per hour (mph). 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. The first numeric speed limit for automobiles was the limit introduced in the United Kingdom in 1861. the highest posted speed limit in the world is , applied on two motorways in the UAE. Speed limits and safety distance are poorly enforced in the UAE, specifically on the Abu Dhabi to Dubai motorway - which results in dangerous traffic, according to a French-government travel-advisory. Additionally, "dr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Traffic Psychology
Traffic psychology is a discipline of psychology that studies the relationship between psychological processes and the behavior of road users. In general, traffic psychology aims to apply theoretical aspects of psychology in order to improve traffic mobility by helping to develop and apply crash countermeasures, as well as by guiding desired behaviors through education and the motivation of road users. Behavior is frequently studied in conjunction with crash research in order to assess causes and differences in crash involvement. Traffic psychologists distinguish three motivations of driver behavior: reasoned or planned behavior, impulsive or emotional behavior, and habitual behavior. Additionally, social and cognitive applications of psychology are used, such as enforcement, road safety education campaigns, and also therapeutic and rehabilitation programs. Broad theories of cognition,doi: 10.1016/0042-6989(93)90252-R/ref> sensory-motor and neurological aspects psychology are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
