A curb extension (or also neckdown, kerb extension, bulb-out, kerb build-out, nib, elephant ear, curb bulge,"curb bulb" and blister) is a traffic calming measure, primarily used to extend the sidewalk, reducing the crossing distance and allowing pedestrians about to cross and approaching vehicle drivers to see each other when vehicles parked in a parking lane would otherwise block visibility.
A curb extension is an angled narrowing of the roadway and a widening of the sidewalk (pavement or footway in UK usage). This is often accompanied by an area of enhanced restrictions (such as a "no stopping" or "no parking" zone) and the appropriate visual reinforcement. This is achieved using painted road markings (e.g. lines, coloured areas, or chevrons), barriers, bollards, or the addition of pavement or street furniture (e.g. planters, lamp standards, or benches).
Curb extensions are often used in combination with other traffic calming measures such as chicanes, speed bumps, or rumble strips, and are frequently sited to "guard" pedestrian crossings. In these cases the "squeeze" effect of the narrowed roadway shortens the exposed distance pedestrians must walk.
... and Bicycle Information Center advises that curb extensions ought not encroach on travel lanes, bicycle lanes, or shoulders, and should not extend more than 1.8 m (6 ft) from the curb ... Some curb extensions are built with the bike lane passing through (making the extension an island, separated from the main sidewalk by a narrow bike lane) ... One study has found that pedestrians crossing at curb extensions have to wait for fewer vehicles to pass before a motorist yields to allow them to cross ...
Famous quotes containing the words extension and/or curb:
“We are now a nation of people in daily contact with strangers. Thanks to mass transportation, school administrators and teachers often live many miles from the neighborhood schoolhouse. They are no longer in daily informal contact with parents, ministers, and other institution leaders . . . [and are] no longer a natural extension of parental authority.”
—James P. Comer (20th century)
“A youthful mind is seldom totally free from ambition; to curb that, is the first step to contentment, since to diminish expectation is to increase enjoyment.”
—Frances Burney (17521840)