Guidelines of Transit-Oriented Development
By: Chris Harpstrite
Several sources write about designing different elements of walkable neighborhoods. Overall conclusions on active walkable streets:
Sidewalks – required on all public streets. Allocate space for plantings and street furniture, sidewalk dining or vendors, and a clear walkway for pedestrians
Building placement and orientation – buildings should be oriented to the street with small or zero setback. Corner buildings are particularly important and are generally required to hold the corner with facades on both streets. Arlington County established the following for main street and pedestrian/open space linkages:
Maintain a recognizable enclosure of space along main street, and primary and secondary connectors by placing buildings, walls, and other features at the edge of the sidewalk, respecting the “build to” line.
Along main street the retail base on buildings should come out to the edge of the sidewalk helping to create an active pedestrian environment and clearly defining the streetscape.
Entrances – primary entrances open onto public streets. This orientation ensures pleasant and simple access for pedestrians.
Windows are frequently required at ground level, and a certain percentage of glass is often specified. The intent is to “enliven” the street by providing visual interest that encourages people to walk and take transit. Requiring fenestration goes hand in hand with avoiding blank walls on pedestrian streets.
Block size – small blocks are generally required in order to create a high level of connectivity that provides a choice of routes for travelers, active walking environments, and the opportunity for diversity in design. Addison, Texas, mandates blocks with between 200’-600’. The length of any block should generally be 200’-250’ long, and never longer than 350’.
Placement and supply of parking – generally zoning defines the placement and supply of parking. Prominent surface parking is consistently and correctly prohibited in transit districts.
Street standards – Streets that are comfortable for walking are essential to TOD districts, and all elements of the street design are frequently addressed.
Building density and intensity – Though density and concentration of activity sufficient to support transit operation are TOD essentials, there is no absolute density standard for TOD. While conventional practices limit the amount of density, with TOD a minimum density needs to be set. Density gradients are usually used, with lower densities (and heights) at the perimeter of the property and higher density at the center, reflecting the fact that the TOD is generally the highest density development in the neighborhood.