Roads Maintenance — Glossary of common road terms

Alley: A privately maintained thoroughfare, tract, or easement, usually narrower than a street, which provides access to the rear boundary of one or more lots and is, not intended for general traffic circulation.

Auxillary lane: The portion of the roadway adjoining the traveled way for parking, turning or other purposes supplementary to through-traffic movement.

Bulb: A round area for vehicle turnaround typically located at the end of a cul-de-sac street.

Bridge: A structure spanning and providing passage over an obstacle, such as a waterway.

Cul-de-sac: A short street having one end open to traffic and the other temporarily or permanently terminated by a vehicle turnaround at or near the terminus.

Culvert: A conduit or conveyance structure under a roadway that is used to pass stream flow, storm water runoff or wildlife to improve safety, prevent accidents and improve traffic flow on the roadway. A culvert has a diameter or width of not more than 20 feet. Any crossing exceeding 20-feet in width is considered a bridge, length is not considered in the definition and is measured perpendicular to the direction of traffic on the roadway.

Driveway: A privately maintained access to residential, commercial or industrial properties.

Easement: Allows another person the right to use private land for a specific purpose.  The most usual easements are those granted to public utility companies to run lines on or under private property.  Other common easements are for storm drainage pipes and ditches, for walkways, and for access roads.

Endangered Species Act of 1973 (ESA), as amended: Federal legislation intended to provide a means whereby the ecosystems upon which endangered and threatened species depend may be conserved, and provide programs for the conservation of those species, thus preventing extinction of native plants and animals.

Erosion Control Best Management Practices (BMP’s): Schedules of activities, prohibitions of practices, physical structures, maintenance procedures and other management practices to reduce pollution or to provide habitat protection/maintenance.

Eyebrow: A partial bulb located adjacent to the serving road that provides access to lots and serves as a vehicle turnaround.

Loop: Road of limited length forming a loop, having no other intersecting road, and functioning mainly as direct access to abutting properties.  A loop may be designated for one-way or two-way traffic.

National Pollutant Discharge Elimination System (NPDES): The part of the federal Clean Water Act, which requires point source discharges to obtain permits. These permits are referred to as NPDES permits and, in Washington State, are administered by the Washington State Department of Ecology.

Private Street: A privately owned and maintained access provided for by a tract, easement or other legal means, typically serving three or more potential dwelling units.

Public Street: Publicly owned facility-providing access, including the roadway and all other improvements, inside the right-of-way.

Resurfacing: The addition of a layer or layers of paving material to provide additional structural integrity, improve serviceability, and rideability.

Right-of-Way: Public land, property, or property interest (e.g., an easement), usually in a strip, as well as bridges, trestles, or other structures, acquired for or devoted to transportation purposes. This does not include recreational or nature trails except where they intersect with or are located within road rights-of-way.

Shoulder: The paved or unpaved portion of the roadway outside the traveled way that is available for emergency parking or non-motorized use.

Sinkhole: Deep or large voids underneath the roadway surface.

Unmaintained county right-of-way: A road within the county right-of-way that is accessible to public travel but is not maintained by the County.

Utility: A privately, publicly, or cooperatively owned line, facility, or system for producing, transmitting, or distributing communications, cable television, power, electricity, light, heat, gas, oil, crude products, water, steam, waste, or any other similar commodity which directly or indirectly serves the public. Additionally, the privately, publicly, or cooperatively owned company that owns the line, facility, or system.

4(d) Rule: The protective rule promulgated by the lead federal agency. This rule is developed only for a single species at a time. The content of a 4(d) rule may be a restatement of Section9(a) prohibitions on take of a species, but also may specify activities which have been determined to be adequately regulated and therefore can be given legal coverage for the (incidental take) of the listed species.

Glossary

Visit our glossary for an explanation of common road terms and jargon.

Contact us

Also see: Additional contact information

Updated: Nov. 7, 2006