Guest Commentary

Decoupling Cars and People

By Robert Puentes

The City of Falls Church grew impressively in recent years. Consistent with the city’s Comprehensive Plan, almost all that growth is concentrated along the major commercial corridors of Broad and Washington Streets. It’s resulted in significant economic returns, promoted business growth, and breathed life and vitality into a slumping city.


Despite this success, new development proposals are met at their start with concerns that they will inevitably cause traffic levels to increase. This ironclad certainty is intuitive to many: more people means more cars which, in turn, means more driving on city streets.


The thing is, it isn’t true. Since 2007, traffic on Broad Street, Washington Street, West Street, and Hillwood Avenue declined in absolute numbers.


We know this because the VDOT helpfully collects data from sensors on streets in each jurisdiction in the Commonwealth. The agency then estimates annual average daily traffic (AADT) for each roadway segment. This data is useful for evaluating pavement performance and for future planning.


It also allows us to compare traffic from year to year to understand trends in traffic volume. I collected all the data for the City of Falls Church since 2007 (I excluded 2020 given the Covid-related drops in travel) since that was about the time when mixed-use development started to take off. The Byron and the Spectrum were both built in 2007, the Broadway in 2004. The VDOT data covers 61 roadway segments in the city, including the entire lengths of major streets like Broad, Washington, Hillwood, and Roosevelt. It also includes the entirety of important streets like West, Lincoln, Oak, Columbia, Cherry, Annandale, along with both Little and Great Falls.


The data is revealing. The state estimates that traffic volume dropped by a remarkable 9.3 percent from 2007 to 2019. That’s based on the combined volumes on all the streets VDOT measured and means we are seeing more than 50,000 fewer vehicles each day. Nearly 96 percent of this drop took place on the four busiest roads.


Where did all the cars go? While the data alone does not provide a precise reason for the drops, there are several plausible explanations. For one, the city is no longer as attractive as a “cut through” as it was in the past. With major employment centers surrounding the city, Falls Church’s streets were designed primarily to move vehicles, and for decades they did it well. Now with all the mixed-use development bringing impediments to speeding traffic, drivers are looking elsewhere.


It is also evident that public and private investments in bicycle, pedestrian, and transit infrastructure are paying off. When other travel options are made available, people use them. When activities are clustered together, people can “chain” their trips together more efficiently, resulting in less traffic. When concentrated in dense patterns, those trips are likely to be accomplished without a car.


The data also shows that, while overall traffic levels dropped significantly, several neighborhood streets did see increases like Lincoln, Marshall, and Oak. It is important to keep in mind that these increases are tiny compared to the huge drops on the major roads, but these are clearly the places where traffic calming and pedestrian-oriented investments should be prioritized.


In addition, we need to continue to reform our outdated parking requirements. Developers know their projects can be successful and avoid spillover onto surrounding streets, without all the parking the city requires them to build. At an average cost of approximately $50,000 per underground space, the over-requirement of parking leads to economic inefficiencies and a reduction in community benefits that could otherwise result from a project, such as better environmental sustainability, more affordable housing, or greater commercial commitments.


The way we forecast future traffic also needs a makeover. Traditional models always assume vehicle volumes increase over time, and therefore assign failing grades for city streets and warn of traffic calamities. However, the VDOT data for Falls Church shows this is not always the case. The population growth over the last dozen years has not brought the traffic nightmares as predicted and, in fact, the opposite is true.


The bottom line is, from a traffic perspective, Falls Church’s plan to accommodate mixed-use development along its major commercial corridors is working and the increase in the city’s population in recent years has not brought the expected increase in automobile traffic. We need to question the assumption that more people means more cars because it diverts time, money, and resources away from the things we say we want.