TOD or Transit-Adjacent Development

by Patrick Siegman, in Tumlin and Millard-Ball


What’s the difference between a true transit-oriented development, which will deliver
promised social and economic benefits, and a transit-adjacent development? A true TOD will include most of the following:

• The transit-oriented development lies within a five-minute walk of the transit stop, or about a quarter-mile from stop to edge. For major stations offering access to frequent high-speed service this catchment area may be extended to the measure of a 10-minute walk.

• A balanced mix of uses generates 24-hour ridership. There are places to work, to live, to learn, to relax and to shop for daily needs.

• A place-based zoning code generates buildings that shape and define memorable streets, squares, and plazas, while allowing uses to change easily over time.

• The average block perimeter is limited to no more than 1,350 feet. This generates a fine-grained network of streets, dispersing traffic and allowing for the creation of quiet and intimate thoroughfares.

• Minimum parking requirements are abolished.

• Maximum parking requirements are instituted: For every 1,000 workers, no more than 500 spaces and as few as 10 spaces are provided.

• Parking costs are “unbundled,” and full market rates are charged for all parking spaces. The exception may be validated parking for shoppers.

• Major stops provide BikeStations, offering free attended bicycle parking, repairs, and rentals. At minor stops, secure and fully enclosed bicycle parking is provided.

• Transit service is fast, frequent, reliable, and comfortable, with a headway of 15 minutes or less.

• Roadway space is allocated and traffic signals timed primarily for the convenience of walkers and cyclists.

• Automobile level-of-service standards are met through congestion pricing measures, or disregarded entirely.

• Traffic is calmed, with roads designed to limit speed to 30 mph on major streets and 20 mph on lesser streets.

Transit Oriented Development: Defined

Transit Oriented Development (TOD) refers to residential and Commercial Centers designed to maximize access by Transit and Nonmotorized transportation, and with other features to Encourage Transit Ridership. A TOD neighborhood has a center with a rail or bus station, surrounded by relatively high-density development, with progressively lower-density spreading outwards. For example, the neighborhood center may have a transit station and a few multi-story commercial and residential buildings surrounded by several blocks of townhouses and small-lot single-family residential, and larger-lot single-family housing farther away. TOD neighborhoods typically have a diameter of one-quarter to one-half mile (stations spaced half to 1 mile apart), which represents pedestrian scale distances. It includes these design features (Morris, 1996):

• The neighborhood is designed for Cycling and Walking, with adequate facilities and attractive street conditions.


• Streets have good Connectivity and Traffic Calming features to control vehicle traffic speeds.


• Mixed-use development that includes shops, schools and other public services, and a variety of housing types and prices, within each neighborhood.


• Parking Management to reduce the amount of land devoted to parking compared with conventional development, and to take advantage of the parking cost savings associated with reduced automobile use.

Transit Oriented Development generally requires at least 6 residential units per acre in residential areas and 25 employees per acre in Commercial Centers, and about twice that for premium quality transit, such as rail service (Pushkarev and Zupan, 1977; Ewing, 1999; Robert Cervero, et al, 2004). These densities create adequate transit ridership to justify frequent service, and help create active street life and commercial activities, such as grocery stores and coffee shops, within convenient walking distance of homes and worksites. However, other factors are also important beside simple density. Transit ridership is also affected by factors such as employment density and Clustering, demographic mix (students, seniors and lower-income people tend to be heavy transit users), transit pricing and rider subsidies, Parking Pricing and Road Tolls, the quality of transit service, the effectiveness of transit Marketing, walkability, and street design. A particular density may be inadequate to support transit service by itself, but becomes adequate if implemented with a variety of Transit Encouragement and Smart Growth strategies. The assumption that transit cannot be effective except in large cities with high population densities can be a self-fulfilling prophecy, because it results in transport and land use decisions that favor automobile travel over transit.