List of road-related terminology

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This is a list of road-related terminology. Both professionals working for departments of transportation and roadgeeks have popularized jargon related to roads, highways, highway systems, streets, and signs.

Contents
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Top of page — See also — External links

[edit] B

button copy

An older style of road sign using button-shaped reflectors to increase nighttime visibility of the sign.

[edit] C

cloverleaf interchange

A type of interchange consisting of eight ramps, four loop ramps and four straight ramps. Each direction of a highway has two exits to the other highway, one for each direction.

concurrency

An overlap of two or more highways. Also referred to as multiplex, with duplex, triplex, etc. referring to the number of highways involved in the concurrency.

cross-pledging

Using toll revenue obtained from one turnpike to finance another owned by the same agency. Cross-pledging is used by the Oklahoma Turnpike Authority to maintain turnpikes that could not sustain themselves.^[1]

cut-out

A shield blank whose external edge is cut to match the shape of the actual shield printed on it. Most highway shields are printed on a square blank, with a black background taking up the border space. Cut-out shields were most often used in the early days of the numbered highway systems in the United States. The standard Interstate shields are still cut-out. California is the only state that still specifies cut-out shields for U.S. and state highways.

[edit] D

decommission

To remove a highway, in whole or in part, from the state highway system. The physical roadbed typically remains usable. The highway may then receive a "lower" designation, such as a U.S. route becoming a state or county route. A decommissioned highway may not receive a new highway designation, but may become a city street or a county- or township-maintained road.^{[2][3][citation needed]}

demountable copy

A style of road sign where each character of the sign's legend is a separate, cut out piece of metal, attached to the sign face using rivets, screws, or some other fastener. This allows for easy modification of the sign's text when needed. Used in only a few states in the U.S., notably Kansas.

diamond interchange

A common type of interchange involving four ramps, one in each quadrant. Diamond interchanges are simple to build, requiring a relatively small number of ramps, only one bridge, and allow all possible movements. However, the intersection of the ramps with the non-freeway road require some form of traffic control, like a traffic light or stop signs, making them less suited to interchanges with heavy traffic.

dumbbell interchange

A variation of the diamond interchange with roundabouts where the ramps intersect the non-freeway road. Most often found in the U.K. Named as such because the two roundabouts and the bridge connecting them resemble a dumbbell when seen from an areal view.

duplex

See concurrency.

[edit] I

interchange

a series of ramps connecting a freeway or motorway to some other road. Interchanges are safer than an at-grade intersection, but cost more to construct.

[edit] J

jughandle

A ramp used to facilitate turns, especially left turns. Most often used in New Jersey, with a few in the surrounding states.

[edit] M

Michigan left

A maneuver required when a left turn is prohibited, as in much of the U.S. state of Michigan, which involves turning right at the desired street and making a U-turn.

multiplex

See concurrency.

[edit] N

neutered shield

An Interstate shield which lacks the name of the state above the route number.

[edit] P

partial interchange

An interchange that is missing one or more ramps, making some movements impossible. Partial interchanges are built when consecutive interchanges are spaced too tightly to allow all ramps to be built safely, or when a movement would make no sense (such as going from eastbound I-240 to westbound I-40 in Oklahoma City) or would be executed rarely enough that it would not justify the cost of building the ramp.

[edit] R

roadgeek

A hobbyist who enjoys traveling and/or studying roads and or road systems. Also road enthusiast or roadfan.

[edit] S

slip ramp

U.K. term for "exit ramp".

SPUI

Abbreviation for single point urban interchange. A variant of the diamond interchange most often used in urban areas that only requires one traffic signal.

[edit] T

terminus

The end point of a highway. Signage denoting the end of the route may be present at the terminus.

Texas U-turn

A lane allowing cars traveling on one side of a one-way frontage road to U-turn into the opposite frontage road (typically crossing over or under a freeway or expressway) without being stopped by traffic lights or crossing the highway traffic at-grade. Also referred to as a Texas Turnaround.

trumpet interchange

A type of interchange used for a "T"-junction where a road or highway ends at a freeway.

[edit] U

useless concurrency

A concurrency between a highway's terminus and the point where it splits off on an independent alignment. The concurrency is "useless" because the highway could have just as well ended at the point it intersected with the concurring road, rather than being extended to some other point by means of a concurrency.

[edit] W

wrong-way concurrency

A concurrency between two roads with opposite signed directions, e.g. a westbound highway and an eastbound highway. Often, the physical roadbed is actually headed in a totally different cardinal direction.

[edit] References

[edit] External links

• AARoads Glossary