When Less Is More

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 Transport- ation 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.”


The U.S. 29 access management zone. (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.


Parallel road systems. (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.

In an era of polarized politics over transportation and land use decisions, access management is one of the few strategies that all sides can agree upon. The smart-growth lobby, which frowns upon the construction of expensive mega-projects like the $200 million U.S. 29 bypass around Charlottesville, favors curtailing access to the highway, especially in the congested growth corridor north of the city. The goal is to divert as much local traffic onto parallel roads while also encouraging drivers to substitute car trips for walking, biking and mass transit.

“Access management was among the reforms pursued in 2007 as part of a bipartisan effort … because it’s a more cost effective approach,” says Stewart Schwartz, executive director of the Coalition for Smarter Growth. Protecting the throughput of rural highways can save hundreds of millions of dollars that otherwise would be needed for costly bypasses.

Likewise, Sen. Stephen D. Newman, R-Lynchburg, who lobbied for years to build the Charlottesville Bypass in order to improve Lynchburg’s access to northern destinations, concurs that VDOT cannot lay down enough asphalt to reduce congestion on U.S. 29 if it can’t control access to the highway. “It’s a road that functions in place of an Interstate,” he says. “Access management has to be part of [the solution]. I would favor becoming more aggressive on access management. That’s where Charlottesville and I would agree.”

There is also a strong fiscal argument to be made in favor of access management. After the McDonnell administration spends the $3 billion in bond proceeds authorized for transportation projects, the well will run dry. Nearly $1 billion of that borrowed money will have to be repaid from anticipated federal transportation revenues, even as maintenance costs eat into new construction funds. To keep roads running smoothly, VDOT will have no choice but to think more creatively about how to increase the capacity of existing roads.

Bow tie U-turn (top) versus traditional U-turn.


 

 

The Lynchburg office showed that can be done. In Phase 1, the state restricted access to four median crossovers (openings in the median strip). Two were closed completely, a third was closed to all traffic except emergency vehicles, and a fourth was modified so that cars traveling west could turn into a convenience store on the highway but cars leaving the store could turn only right. To facilitate the U-turn without having cars slow down to pull into the crossover, thus crimping traffic flow, VDOT installed an inexpensive “jug handle” intersection in which cars veered right onto a deceleration lane and emptied onto a signaled intersection.

Phase 2 will seek to provide alternate routes for residences and businesses on the highway or, failing that, purchase them outright. Businesses affected include a truck-body repair facility, a restaurant and Falwell Airport, a general aviation airfield. As necessary, VDOT will add acceleration and deceleration lanes.

VDOT’s Cary likens the approach to cleaning out the corroded insides of a pipe. “A smooth pipe carries more water than a corrugated pipe,” he says. The capacity of the revamped U.S. 29/460 will be less than a restricted access highway but it will be much superior to what it had been. “We’re getting most of the benefit – maybe 65% to 70% -- of a completely limited access highway,” says the district administrator. Plus, he adds, if VDOT ever does have the funds to upgrade that stretch of road to a freeway, “A lot of those changes would have to be made anyway. They align with the long-term vision for the highway.”

=============

This article was reported and written thanks to a sponsorship by the Piedmont Environmental Council.

Edit

Leave a Reply

Logged in as admin. Log out?

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>