Development need not clog the roads

Arlington County, Virginia, has shown that a suburban county can add plenty of housing, offices, and retail space without placing much additional burden on the roads. Between 1996 and 2006 Arlington added 8,300 dwellings, 4.14 million sq. ft. of offices, more than 1.1 million sq. ft. of retail, and over 1,000 hotel rooms, according to Dennis Leach, the county’s transportation director. Yet arterial roads in areas gaining the most development — all of them served by Metro rail stations — experienced either a decrease or only a modest increase in vehicular traffic. In the booming area around the Clarendon Metro station, vehicular traffic fell 16 percent on one thoroughfare, Wilson Boulevard, and rose 4 percent on another thoroughfare, Clarendon Boulevard, Leach says. Overall traffic growth on the county’s arterial roads was “extremely modest, half a percent or less per year,” during that period, Leach says. Transit use in the county rose 37.5 percent, including a 43 percent growth in Metro rail ridership during the years Leach studied. Though commuter rail clearly played a part in restraining the growth of auto traffic, Leach suggests that the county’s expansion of a local bus service, which went from carrying 100,000 to carrying 926,000 riders a year, contributed to the situation. Other policies and programs that helped were transportation demand management; a lowering of parking requirements; a mandate that commercial buildings price their parking at market rates; effective commuter information; programs to encourage alternative models of travel; construction of sidewalks and bicycle facilities; and a robust car-sharing program.