Sometimes, the cure for traffic congestion isn’t more asphalt, it’s less. By managing local vehicular access to state highways, VDOT can increase capacity at lower cost.By James A. Bacon

The Virginia Department of Transportation created a problem when it built the U.S. 29 Bypass around Lynchburg, merging it with U.S. 460 for about 10 miles southeast of the city. While most of the shared roadway was limited access, allowing cars and trucks to move freely, a 1.7-mile section near Falwell Airport was used heavily by local traffic.

Vehicles traveling at highway speeds do not mix well with vehicles pulling out of restaurants, driveways and industrial access roads. In the 18 months before the bypass completion, the crash rate on that stretch of road was 16 per one million vehicle miles driven (VMD). In the 18 months following, the crash rate surged to 102 – more than six times higher.

Clearly, something had to be done. Upgrading that 1.7-mile stretch to a full limited access highway with exit ramps would have cost between $50 million and $55 million, says Rob Cary, VDOT’s Lynchburg district administrator. That seemed like a lot of money. Instead, VDOT adopted a strategy of pruning local access points to the highway. Since the completion two months ago of Phase 1 at a cost of $1.5 million, the number of crashes has been… zero. That safety streak won’t last forever, but a second phase costing $11.7 million should make the road even safer. Says Cary: “We get a lot of the benefit for one-third the cost.”

(Click on map for more legible image.)    

Access management is not a novel concept, but its application to Virginia roads is relatively new. Only in 2007 did the General Assembly direct VDOT to develop access-management regulations and standards with the goal to reduce traffic congestion, enhance public safety and reduce the need for new highways. The rules cover such aspects of design as the location and spacing of entrances, intersections, median openings and traffic signals. Since 2007, principles of access management have started turning up in VDOT documents such as the U.S. 29 Corridor of Statewide Significance (CoSS) plan.

U.S. 29, known as the Lee Highway in Virginia, stretches 1,000 miles from Pensacola, Fla., to Baltimore. Like other highways across the United States, U.S. 29 attracted commercial and residential development in the metropolitan regions it served as land owners exploited their proximity to a major transportation artery. But each new gas station, fast food outlet, shopping center and cul de sac neighborhood required an access point and an increasing share of the traffic became purely local. With traffic came signaling lights. As ever more vehicles halted at stoplights and pulled into the highway from driveways and store entrances, travel speeds decayed and congestion worsened.

The traditional response to highway congestion in Virginia was the bypass. When highway traffic bogged down on U.S. 29 in Danville, Lynchburg, Charlottesville, Culpeper and Warrenton, VDOT simply ran a new, limited access highway around the congestion. When the bypass got gummed up like the original highway, VDOT build another bypass. Warrenton has two, and Charlottesville is about to get a second one.

The Rt. 29 Corridor Plan fleshes out the new way of thinking in considerable detail. The vision for the corridor is one that allows access to the highway only at “designated and appropriately spaced locations.” VDOT and local governments along the route can clean up the accumulated detritus through a number of techniques, such as:

•    Changing zoning to shift growth pressures away from properties immediately adjacent to Route 29.
•    Putting land along the highway into conservation easements.
•    Having VDOT purchase access rights-of-way.
•    Developing parallel road systems to take local traffic off the highway.

   (Click on graphic for more legible image.)

•    Employing novel roadway designs such as roundabout crossovers and bowtie U-Turn configurations.
•    Requiring plans for any new traffic signal to have an “exit strategy” for removing the signal at some point in the future. Read more.