The results of a series of in-depth travel surveys released by the Transportation Planning Board in March highlight key differences in how people live and travel in higher-density areas with greater proximity to transit compared to those with lower densities and fewer travel options.
Of the seven surveyed areas, the three with the highest population densities were home to households with fewer people, often in apartment buildings or condominiums, and to households that made a greater share of their trips by travel modes other than private automobile. The three areas with the lowest population densities were home to larger households, often with children, and to households that made more of their trips by car.
The TPB carried out the in-depth surveys in early 2012, bringing to 17 the total number of areas it has surveyed since 2010. The results of the in-depth surveys supplement the findings of a similar but less concentrated survey of the entire region conducted in 2007 and 2008.
Both surveys asked all the members of selected households to complete travel diaries detailing the origin and destination, travel mode, travel time, and purpose of every trip they made in a given day. The TPB uses the findings to refine its travel forecasting models, and local planners have been using the data as they conduct studies and develop plans for future transportation projects or new development.
The results of the most recent surveys highlight the relationship between population density, household characteristics, available travel options, and travel patterns.
Among the areas surveyed, the three survey areas with the highest population densities were the Beauregard Street corridor near the Mark Center in Alexandria, the New York Avenue and Rhode Island Avenue corridor in Northeast Washington, and the Friendship Heights area in Northwest Washington and parts of Montgomery County. These three areas had the highest shares of one-person households and the lowest shares of households with children among all seven survey areas. They also had the highest share of commute trips by transit.
The three study areas with the lowest population densities were the National Harbor/Oxon Hill area in Prince George's County, the St. Charles/Waldorf area in Charles County, and the area just north of Dulles Airport in Loudoun County. These three areas were all home to larger households, often with children, which typically find car travel much easier than other options like transit, bicycling, or walking. They also had significantly lower shares of commute trips by transit, all falling well short of the regional average of 18%.
The seventh of the study areas -- the area around the East Falls Church and West Falls Church Metrorail stations -- showed more of a blend of household characteristics and travel patterns. The area tended to have shares of single-person households and households with children more reflective of lower-density areas but shares of commute trips by transit more similar to higher-density areas.
This study area's proximity to two Metrorail stations and its mix of housing options make such a blend more possible, and it demonstrates the possibility of providing family-friendly housing options in areas close to transit, making options other than driving more convenient for more people. The challenge for local and regional planners looking to reduce dependence on car travel by focusing more development near transit will be to provide ample housing options near transit that cater to more than just young, single professionals or older adults with grown children.
Later this year, the TPB will survey an additional ten areas, adding to the library of detailed information on household characteristics and travel patterns in parts of the region with different densities, physical characteristics, and transportation options.