Full Sidewalk
A sidewalk is the portion of a street, intended for the use of pedestrians, between the roadway and adjacent property lines. A full sidewalk accommodates both pedestrian traffic and a range of street furnishings and fixtures. The area of the sidewalk closest to the curb, where light poles, tree pits and other vegetation, signs, fire hydrants, and street furniture are typically located, is referred to as the “furnishing zone.”
Ribbon Sidewalk
A sidewalk that is separated from the roadway by a continuous, unpaved planting strip. Most existing ribbon sidewalks in the city have a lawn planting strip, more sustainable landscaping options should be utilized whenever possible. Alternatively, planting strips can be designed as pilot Stormwater Management Practices to help collect stormwater runoff.
Pedestrian Ramp
Pedestrian ramps are a critical component in providing safe and accessible means of travel. Pedestrian ramps provide safe transitions between the roadway and sidewalk and are an essential tool for all pedestrians, particularly the aging population and people with ambulatory and vision disabilities. Ramps are required to include a color-contrasting detectable warning surface to communicate boundaries between pedestrian and vehicular paths and unprotected drop-offs to pedestrians who have vision disabilities.
Curb Extension
An expansion of the curb line into the lane of the roadway adjacent to the curb (typically a parking lane) for a portion of a block either at a corner or mid-block. Also known as neckdowns, curb extensions can enhance pedestrian safety by reducing crossing distances, can relieve sidewalk crowding, and can provide space for functional elements such as seating, plantings, bike share stations, and furniture. In addition, two curb extensions can be located on either side of a street to create a Mid-Block Narrowing or at an intersection to create a Gateway.
Mid-Block Narrowing
Two curb extensions that create a pinch point. A mid-block narrowing (also referred to as a “choker”) physically or visually constricts the roadway, thereby slowing vehicular traffic or alerting drivers to the presence of a mid-block crosswalk. The curb extensions themselves can be of any variety, for example with plantings or other functional elements. A mid-block narrowing is equivalent to a Gateway located mid-block.
Bus Bulb
A curb extension at a bus stop that allows buses to remain in the moving lane while picking up and discharging passengers. Bus bulbs may also be designed to better support bus passengers through the inclusion of higher curbs, bus stop shelters, seating, pre-boarding payment equipment, and other bus-supportive facilities.
Bus Boarding Island
A raised area, not connected to the adjacent sidewalk, with dedicated waiting and boarding area for bus passengers. Boarding islands provide many of the benefits of bus bulbs while also avoiding curb, bike, and catch-basin conflicts. Usage is most desirable on streets with parking-protected bike lanes and frequent bus service.
Raised Median
A raised area separating different lanes, traffic directions, or roadways within a street. The raised median can be either curb height (6–7 inches) or, where appropriate, 12 – 24 inches high. The width as well as design of raised medians can vary widely. They can range from narrow raised concrete islands to tree-lined promenades to intensively landscaped boulevard medians. In contrast to Pedestrian Safety Islands, raised medians extend for most or all of the street block.
Pedestrian Safety Island
A raised area located at crosswalks that serves as pedestrian refuge separating traffic lanes or directions, particularly on wide roadways. Also known as a “median refuge island.” Used at pedestrian crossings when a full raised median is not feasible. A pedestrian safety island confers most of the same benefits as a full Raised Median at pedestrian crossings. Full raised medians should be used rather than pedestrian safety islands wherever possible.
Median Barrier
A Raised Median or Pedestrian Safety Island extended through an intersection to prevent turns and through-movements to and from the intersecting street. Pedestrian access can be maintained with pedestrian refuges and bike access with gaps in the median. As with typical raised medians, trees or plantings can be included within the median barrier.