Transit-Oriented Development - Does It Increase Ridership?
Transit-Oriented Development (TOD) refers to new construction designed to foster patronage of transit services, especially new rail rapid transit lines. TOD is often, but not always, mixed-use, and is always of higher density than its surroundings. This last point is important, as billing something as "transit-oriented" is used by proponents of increasing density to accomplish their objective; it would make no sense to refer to development as "transit-oriented" in central Toronto, Chicago, or New York - by definition all development in the downtowns of above cities is transit-oriented.
The major reason these developments are often allowed to proceed is that many of the additional trips caused by the increased density should theoretically be taken by transit - if these additional trips do not take transit than all the increased density accomplishes is to increase automobile traffic. In other words, if transit-oriented development does not increase transit usage then it is basically a failure.
Without looking at the evidence, one could find plausible assertions to justify each answer to the question if TOD increases ridership. On the plus side, it seems reasonable to believe that TOD increases ridership - being able to take a train almost to the front door of your residence or workplace would certainly make taking the train an attractive opposition. On the negative side, one concern over TOD is that due to the fact that proximity to rail transit often increases property values , the only people who can afford to live in a TOD are wealthier people - and wealthier people do not take transit as much. In fact, concern over gentrification is one concern brought forward by opponents of TOD in an attempt to stop such projects. This concern is somewhat, but not totally, resolved through the provision of low-income housing in TOD projects.
Studies Show That Being Near Transit Increases Transit Ridership
Overall, the studies have found that yes, being near rapid transit increases transit usage. Here are some highlights of studies:
- In 1992-93, surveys found that 32% of workers living near BART stations in the San Francisco Bay area commuted by rail, which was more than six times the regional average of 5%
- People living along the Washington Metro Orange Line corridor in Virginia take transit at a three times higher percentage than the average for all of Arlington County - 39% versus 13%
- In San Jose, CA, TOD residents take transit five times more frequently than county residents as a whole
- At the Center Commons TOD in Portland, OR, transit-mode share increased by almost 50% for work trips and by 60% for non-work trips
- Workers employed in offices near BART stations are 2.5 times more likely to get to work by rail than other San Francisco Bay Area commuters
- 50% of people who work within 1,000 feet of a Washington Metro station in downtown Washington commute by rail
More About Being "Near" Transit
While being near transit does increase transit usage, transit usage falls off sharply as distance from the transit station increases. For example, transit's mode share declines by 0.65% for every 100-foot increase in the distance of a residence from a Washington, D.C. Metro station. In California, this decline is even greater - 0.85% for every 100-foot increase in walking distance. It is possible that effective bus/rail interfaces may attenuate this decline, but to my knowledge it has not been studied. Given that it is unreasonable to expect more than 50% of the residents of a building near transit to commute via transit, this drop-off means that there is very little space available for transit-oriented development at each station, and this development has to compete with other potential uses including park and ride lots . Available system-wide TOD potential is further diminished by the fact that due to concerns about speed and cost, most new rapid transit lines have long distances between stops, with one mile being a typical distance .
TOD Transit Ridership Versus the Completeness of a City's Rapid Transit Network
The study of TOD effects on transit ridership is still in its infancy, and many questions remain. One important one is whether the completeness of a city's rapid transit network affects the transit ridership potential of a TOD. For example, both Washington, D.C. and the San Francisco Bay area, referenced above in studies that showed that TOD increases transit ridership, have very complete rapid transit networks that cover the vast majority of all area of high employment density in the respective metropolitan areas. On the other hand, cities such as Phoenix, Charlotte, and Norfolk only have one rapid transit line each which leaves most of the city uncovered. Would TOD be less successful in those cities simply because the one available line does not provide access to a lot of jobs? The answer to this question is unknown at this time.
The Issue of "Self-Selection"
While TOD can increase transit usage, a concern has been raised that these transit users have chosen to live in the TOD precisely because they wanted to take transit, and did not start taking transit simply because the option had become available. This concern echoes a general concern that the patronage a new rapid transit line attracts is merely existing transit users who choose to use the new line rather than continuing to ride a bus, and not commuters who currently drive. To me, it does not matter who is riding a new rapid transit line as long as it is well-patronized - the money that a new transit convert and a loyal passenger uses to purchase a monthly pass looks the same. Rapid transit and TOD is not about reducing congestion - one transit line cannot accomplish that - rather, it is about giving people a choice. You can choose to live in a TOD, sell your car and use your $5,000 annual savings to go on an exotic vacation, and use your commute time on transit productively - or you can continue to become stuck in gridlock and contract a chronic case of road rage.