curbs

A curb is a raised edge along a street or path that separates the roadway from adjacent spaces such as sidewalks, parking lanes, or private property. It defines the boundary of the carriageway, provides a transition between levels, and works with a gutter system to manage surface water and protect pedestrians and structures from errant vehicles.

In North America the term curb is standard, while in the United Kingdom and many other Commonwealth countries the term kerb is used. Curbs may be vertical or near-vertical, or formed with rounded or mountable profiles to permit occasional vehicle traversal, such as at driveways or narrow streets.

Most curbs are constructed from concrete, but stone, brick, or precast concrete units are common in certain streetscapes. Asphalt can be used for some lighter installations, and some urban designs employ integrated stone or paver edging. Along with the curb, a gutter or drainage channel handles surface runoff.

Key functions include delimiting the traffic surface, guiding drainage toward curb inlets, and providing a barrier that protects pedestrians and adjacent property. Curb geometry, such as radii at intersections and the option of drop curbs for driveways, influences traffic behavior and accessibility.

Maintenance concerns include cracking, spalling, and freeze-thaw damage, plus debris build-up in gutters. Replacement or repair is common on aging roadways, and proper maintenance helps prevent pavement deterioration and preserves pedestrian safety.