Photo by paul.derry on Flickr.

It’s a commonly accepted axiom among many of the contributors of this blog that freeway tolls help drivers internalize the cost of their housing and transportation decisions. Could Virginia use tolls as a substitute for a statutory growth boundary?

Tolls are one item in the cost-shifting bucket sometimes available to governments to affect demand, along with “vehicle-miles traveled” fees and gas taxes. In typical fashion, however, these all have a relatively linear impact on driving distances. That is, for every extra X miles travelled, the driver must pay $Y more. When a prospective home buyer seeks a new house, then, choosing a cheaper property “just one exit more down” affects his cost calculation only subtly.

Given the small marginal cost difference in driving just one more exit, even in the presence of tolls, some progressive governments have experimented with other options to control growth at a hard-and-fast boundary. Perhaps the most famous example is Portland’s Urban Growth Boundary. Other approaches include cutting off urban services (like sewer connections) beyond a certain point or using transferable development rights (TDRs) with large multipliers to drive growth away from agricultural areas. The ability for jurisdictions to implement these approaches, however, varies state by state.

Compared to many states, Virginia localities are more restricted in their ability to control growth past a boundary. For instance, Fairfax County was prohibited (partially on a technicality) by the Supreme Court of Virginia in 1959 from downzoning the western two-thirds of the County to larger two-acre lots in order to lessen growth there and encourage it in a denser form in the areas closer to Falls Church, Arlington, and Alexandria. (See Board of Supervisors v. Carper, 200 Va. 653.) One of the fears suggested by the Court over the years has been that restricting large areas from development would serve to increase prices county- or region-wide, unconstitutionally excluding low-income Virginians from finding homes. In recent decades, similar growth-controlling policies by other counties have been attempted with varying degrees of success, but the localities find themselves in court over the regulations virtually every time.

Moreover, attempts such as Fairfax’s struck-down 1959 large-lot ordinance often act as blunt tools. Though a region may be interested in controlling sprawling growth emanating from a megacity at its center, such large-lot development policies might have the effect of making housing expensive and car-dependent for the towns on the periphery that are not currently in the direct orbit of the megacity.

It was with this in mind that I recently found the privately owned Dulles “Greenway” toll highway a fascinating case in growth control. Its toll structure works like this: traveling westbound (away from Washington), users pay a toll solely upon entry; traveling eastbound, users pay a toll solely upon exit. At the Greenway’s easternmost terminus (near Dulles Airport at the start of the similarly named but state-owned Dulles Toll Road), the toll is nearly $5, while the first few exits at the western end are free before slowly going up in price as one travels eastbound.

The result is that this road is effectively linearly priced for travelers starting their journey in Leesburg (at the western terminus) but fixed-price for travelers starting their journey near Dulles. This makes using the Greenway an expensive proposition for any driver in this latter group not utilizing the entire length of the facility.

Suddenly, a Tysons commuter who chooses a home off of Old Ox Road or the Loudoun County Parkway doesn’t suffer just a subtly more expensive commute than one who opts for a similar house in Herndon, a mere 3 miles away: it results in upwards of $2,000 a year in added commuting expenses. On the other hand, residents of the Leesburg area who commute only within their town’s region without driving as far as Dulles don’t bear the brunt of the eastern end of the road’s more expensive toll.

My research has left me without an answer as to whether the tolling structure was designed with this purpose in mind (and because it’s a private road that has more ability to self-set its rates, I doubt it), but if it was, I’m impressed.

As policymakers over the next decades increasingly embrace road tolling, such a system might just be the best way to curb sprawl without needlessly angering communities that can be reasonably independent of a central metropolis.