Virginia's new street connectivity regulations: the specifics
As mentioned Monday, new regulations in Virginia will prohibit residential subdivisions composed purely of culs de sac. Instead, the regulations will require that all new neighborhoods connect, or provide provisions to connect, to surrounding streets and properties.
In choosing to study this issue and ultimately promulgate new regulations, the Commonwealth has articulated that it expects a significant cost savings in the future for a variety of reasons. The change will divert public paving and plowing resources from de facto private, low-use roads to those that serve multiple uses. Localities should need fewer emergency facilities, as ambulances and fire companies can better reach farther locations with a better grid of streets. And more directly, it will reduce the pressure to construct additional inefficient roads, turning lanes, and streetlights at great expense.
A better connected street network will free residents from needing to drive on the few large arterials for every trip, as dwellers of exurban life frequently must do, even to go a half-mile to a friend's house in the next subdivision. It also will reduce the subsidy denser-living Virginia residents will have pay to allow others to live on streets that function as private roads for as few as three homes. Additionally, greater "back road" connectivity can generally provide safer options for cyclists off of higher-speed arterials.
Here are some of the specifics of the new regulations, and what they might mean going forward.
Background: In Virginia, as in many other places, the provision of subdivision roads generally sticks to the following process. First, the developer acquires a large parcel. Next, the developer drafts a "plat" showing how he will subdivide the parcel into lots and place the roads. The developer builds the roads, along with other infrastructure, such as storm drains. Finally, VDOT accepts the now-built roads into its "secondary system of highways."
This last step completely dedicates the roadway to the Commonwealth, eliminating any interest the developer once had in the roads, and shifting all future costs to VDOT. In Virginia, VDOT is ultimately responsible for the expensive maintenance and paving of roads it controls. The rules are slightly different in Arlington and Henrico Counties, but the concepts are similar.
Connectivity Index: Previously, while VDOT has had standards for the roads it would accept, including width and turning radius regulations, connectivity hasn't been part of the calculation. To incorporate this concern, the regulations introduce a planning concept called a "connectivity index" to compare various street network proposals. In Virginia's implementation, the number of street "segments" is divided by the number of street "intersections" to generate an index. The higher the ratio, the better. The trick is that culs de sac or any other street termini count as intersections. Meanwhile, "stub out" roads that dead-end at the parcel property line, for connection by other developers on the adjacent parcel later, don't count as intersections. This discourages the former and encourages the latter. For this reason, it might be better to refer to an "intersection" for calculation purposes instead as a "node".
For most population-heavy areas in the state, the required index going forward will be 1.6 segments per node. In less dense areas or projects (lots larger than half-acre or quite a distance outside of urbanized areas), the index drops to 1.4, while large-lot projects (over 2-acres apiece) in truly rural areas have no required connectivity index for acceptance.
Trumping NIMBYs: The road-dedication process is actually more complex than noted above. In reality, the project goes through an ever-lengthening series of negotiations and approvals along the way. Localities have the power to accept or reject subdivision plats, while VDOT gets to accept or reject road dedications (except in Arlington and Henrico, which control both themselves, arguably resulting in much better land planning).
Virginia foresaw that localities, under pressure from residents, might not agree to approve a subdivision plat that is designed to connect with the next project, forcing a road disconnect. If this happens, the regulations call for calculating the connectivity index as if the streets connected in their logical places, and then taking away sufficient amounts of the locality's transportation funds for VDOT to then construct the obvious connections itself. Thus, if a locality tries to block a road connection, it will fail, and then have to pay for the connection out of its own pocket.
The regulations allow for exceptions where there are physical barriers like railroad tracks or rivers, or where the adjacent parcels maintain "incompatible uses". However, in another forward-looking decision, the regulations specifically state that, "[i]n no instance shall any retail, office, or residential land use be considered incompatible land use with any proposed retail, office, or residential development." This explicitly prohibits localities or landowners from contesting a connection to an adjacent apartment complex or shopping center on the basis of "incompatibility".
Pedestrians are traffic too: In a shift from prior language, when road improvements take place, the new regulations require that "traffic, both vehicular and pedestrian, should be maintained ... until the new portion has been accepted."
For more information, there is a stakeholder presentation from December detailing many of these points and more, including new street-width guidelines.
This set of standards represents a refreshing sea change in road (and community) planning in Virginia. The Commonwealth deserves loud commendation for introducing this. To my knowledge, this is the first attempt by a state government, nationwide, to mandate such connectivity, shifting an approach that goes back decades. Unfortunately, though, I expect the practical benefit will be minimal in our region for the foreseeable future. It does nothing to resolve the lack of connectivity in existing middle- and outer-ring suburbs which will last for quite a while, extending up to 20 miles outside the Beltway. On the other hand, it will hopefully protect the communities surrounding the smaller cities and towns in the state, and could guide the redevelopment that may occur in Fairfax, Prince William, and Loudoun Counties fifty or a hundred years from now.
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