The Dwight D. Eisenhower National System of Interstate and Defense Highways, commonly known as the Interstate Highway System, or the Eisenhower Interstate System, is a network of controlled-access highways that forms part of the National Highway System in the United States. The system extends throughout the contiguous United States and has routes in Hawaii, Alaska, and Puerto Rico.
The United States Department of Transportation is one of the executive departments of the U.S. federal government. It is headed by the secretary of transportation, who reports directly to the president of the United States and is a member of the president's Cabinet.
A pedestrian crossing is a place designated for pedestrians to cross a road, street or avenue. The term "pedestrian crossing" is also used in the Vienna and Geneva Conventions, both of which pertain to road signs and road traffic.
Traffic lights, traffic signals, or stoplights – also known as robots in South Africa, Zambia, and Namibia – are signaling devices positioned at road intersections, pedestrian crossings, and other locations in order to control the flow of traffic.
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.
The Manual on Uniform Traffic Control Devices for Streets and Highways is a document issued by the Federal Highway Administration (FHWA) of the United States Department of Transportation (USDOT) to specify the standards by which traffic signs, road surface markings, and signals are designed, installed, and used. In the United States, all traffic control devices must legally conform to these standards. The manual is used by state and local agencies as well as private construction firms to ensure that the traffic control devices they use conform to the national standard. While some state agencies have developed their own sets of standards, including their own MUTCDs, these must substantially conform to the federal MUTCD.
A diverging diamond interchange (DDI), also called a double crossover diamond interchange (DCD), is a subset of diamond interchange in which the opposing directions of travel on the non-freeway road cross each other on either side of the interchange so that traffic crossing the freeway on the overpass or underpass is operating on the opposite driving side from that which is customary for the jurisdiction. The crossovers may employ one-side overpasses or be at-grade and controlled by traffic lights.
The Research and Innovative Technology Administration (RITA) is a unit of the United States Department of Transportation (USDOT). It was created in 2005 to advance transportation science, technology, and analysis, as well as improve the coordination of transportation research within the department and throughout the transportation community.
The National Highway System (NHS) is a network of strategic highways within the United States, including the Interstate Highway System and other roads serving major airports, ports, military bases, rail or truck terminals, railway stations, pipeline terminals and other strategic transport facilities. Altogether, it constitutes the largest highway system in the world.
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 A&M 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.
Annual average daily traffic (AADT) is a measure used primarily in transportation planning, transportation engineering and retail location selection. Traditionally, it is the total volume of vehicle traffic of a highway or road for a year divided by 365 days. AADT is a simple, but useful, measurement of how busy the road is.
The Standard Alphabets For Traffic Control Devices,, is a sans-serif typeface developed by the United States Federal Highway Administration (FHWA). The font is used for road signage in the United States and many other countries around the world. The typefaces were developed to maximize legibility at a distance and at high speed. The typeface has 6 fonts, from narrow to wider strokes:
The Oklahoma Department of Transportation (ODOT) is an agency of the government of Oklahoma responsible for the construction and maintenance of the state's transportation infrastructure. Under the leadership of the Oklahoma secretary of transportation and ODOT executive director, the department maintains public infrastructure that includes highways and state-owned railroads and administers programs for county roads, city streets, public transit, passenger rail, waterways and active transportation. Along with the Oklahoma Turnpike Authority, the department is the primary infrastructure construction and maintenance agency of the State.
The Illinois Department of Transportation (IDOT) is a state agency in charge of state-maintained public roadways of the U.S. state of Illinois. In addition, IDOT provides funding for rail, public transit and airport projects and administers fuel tax and federal funding to local jurisdictions in the state. The Secretary of Transportation reports to the Governor of Illinois. IDOT is headquartered in unincorporated Sangamon County, located near the state capital, Springfield. In addition, the IDOT Division of Highways has offices in nine locations throughout the state.
The Federal Bridge Gross Weight Formula, also known as Bridge Formula B or the Federal Bridge Formula, is a mathematical formula in use in the United States by truck drivers and Department of Transportation (DOT) officials to determine the appropriate maximum gross weight for a commercial motor vehicle (CMV) based on axle number and spacing. The formula is part of federal weight and size regulations regarding interstate commercial traffic. The formula is necessary to prevent heavy vehicles from damaging roads and bridges. CMVs are most often tractor-trailers or buses, but the formula is of most interest to truck drivers due to the heavy loads their vehicles often carry.
Logo signs are blue road signs used on freeways that display the logos or trademarks of nearby businesses before travelers reach an exit or interchange which lead to the businesses. Typically, a business pays a small fee to a transportation department to have their logos displayed on a large panel alongside other businesses. Depending on the jurisdiction, businesses may have to meet certain criteria such as hours of service and distance from the sign.
Lt. Gen. Kenneth Richard Wykle is a retired American Army officer and civil servant who served as Administrator of the Federal Highway Administration under the second Clinton administration.
Long-Term Pavement Performance Program, known as LTPP, is a research project supported by Federal Highway Administration (FHWA) to collect and analyze pavement data in the United States and Canada. Currently, the LTPP acquires the largest road performance database.
The Ohio Manual of Uniform Traffic Control Devices is the standard for traffic signs, road surface markings, and traffic signals in the U.S. state of Ohio. It is developed by the Ohio Department of Transportation's Office of Roadway Engineering "in substantial conformance to" the national Manual on Uniform Traffic Control Devices developed by the Federal Highway Administration. The first edition of the OMUTCD was published in 1924; the most recent edition was published in 2012. Ohio is one of ten states that publish their own editions of the MUTCD.
Transportation in the United States is governed by laws and regulations of the federal government. The Department of Transportation is responsible for carrying out federal transportation policy, and the Department of Homeland Security is responsible for security in transportation.
