Curb extensions are often applied at the mouth of an intersection. When installed at the entrance to a residential or low-speed street, a curb extension is referred to as a “gateway” treatment and is intended to mark the transition to a slower speed street.
Critical
The length of a curb extension should at least be equal to the width of the crosswalk, but is recommended to extend to the advanced stop bar.
Recommended
1A curb extension should generally be 1–2 feet narrower than the parking lane, except where the parking lane is treated with materials that integrate it into the structure of the sidewalk.
Curb extensions should be installed whenever on-street parking is present to increase visibility, reduce the crossing distance, provide extra queuing space, and allow for enhancements, such as seating or greenery.
2Combine stormwater management features, such as bioswales or rain gardens, with curb extensions to absorb rainwater and reduce the impervious surface area of a street.
In advance of a full reconstruction, gateways can be designed using striping or signage that communicates the entrance into a slow zone.
Optional
Curb extensions may be treated with corner street furniture and other amenities that enhance the public realm.
Curb extensions may be combined with bioswales in order to decrease puddling at crosswalks.