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A railroad car.
rail, high speed
A rail transportation system with exclusive right of way that serves densely traveled corridors at speeds of 124 mph (200 km/h) and greater.
rail main line
A principal or well established rail line (Class I rail lines; e.g., Union Pacific and BNSF Railroad).
rail rapid transit
A system operating high-speed, high-capacity passenger trains using an exclusive, fixed right of way.
railway, railroad
A road composed of parallel steel rails supported by ties and providing a track for locomotive-drawn trains or other wheeled vehicles.
raised pavement markers (RPMs)
Used as positioning guides and/or as supplements or substitutes for other types of markings; these markers conform to the color of the marking for which they serve as a positioning guide, can be mono- or bidirectional and are fastened into the pavement with the reflector surface visible above the road surface.
reaction time (RT)
The time from the onset of a stimulus to the beginning of a driver's (or pedestrian's) response to the stimulus, by a simple movement of a limb or other body part.
real-time kinematic global positioning system (RTK-GPS)
This is a satellite navigation technique used in land and hydrographic survey.
reasonably direct
Either a route that does not deviate unnecessarily from a straight line or a route that does not involve a significant amount of out-of-direction travel for likely users.
record of decision (ROD)
The final approval of an environmental impact statement issued by the Federal Highway Administration.
regional transportation needs
Needs for movement of people and goods between and through communities and accessibility to regional destinations within a metropolitan area, county or associated group of counties.
Regional Transportation Plan (RTP)
The official intermodal transportation plan that is developed and adopted through the metropolitan transportation planning process for the metropolitan planning area.
Paid back; in some cases, municipalities must first spend the money before getting funds back from the state.
reinforced concrete
Concrete with steel reinforcing bars bonded within it to supply increased tensile strength and durability.
A federal budgetary term that refers to the cancellation, in whole or part, of budget authority previously granted by Congress.
The regular vibration of an object as it responds in step (at the same frequency) with an external force.
resurfacing program
Provides for pavement resurfacing, rehabilitation, minor reconstruction, and pavement milling and recycling; such projects are intended to preserve the structural integrity of highway pavements.
reverse commuting
Movement in a direction opposite the main flow of traffic, such as from the central city to a suburb during the morning peak period.
The number of people making one-way trips on a public transportation system in a given time period.
The shared use of a vehicle, such as a van or an automobile, to make a trip.
right of way and right-of-way
Right of way
The land (usually a strip) acquired for or devoted to transportation purposes. For example, highway ROW and railroad ROW.

Right-of-way (hyphenated if an adjective, e.g., right-of-way agreement)
A general term denoting land or property acquired for or devoted to transportation purposes, but with other associated uses such as utilities, water and sewage lines and buffer zones.
right turn on red (RTOR)
Unless otherwise specified by traffic control signage, this practice permits a driver to proceed with a right turn on red signal after stopping at signalized intersections. It provides increased capacity and operational efficiency at a low cost.
rigid frame bridge
A bridge with moment-resistant connections between the superstructure and substructure to produce an integral, elastic structure.
riveted connection
A rigid connection of metal bridge members that is assembled with rivets; riveted connections increase the strength of the structure.
Railroad employee in charge of track maintenance.
rolling stock
The vehicles used in a transit system, including buses and rail cars.
A type of road junction (or traffic calming device) at which traffic streams around a central island, after first yielding (giving way) to the circulating traffic.
The sum of the lengths of all the routes in a transit network less any miles duplicated among them.
rumble strips
Driver aids placed in the edges of a roadway pavement.