Work on what's known as a diverging diamond interchange — the first in Virginia, state officials say — is set to begin Wednesday at the bustling intersection of Interstate 64 and U.S. 15, much to the relief of businesses and residents in Zion Crossroads.
Avoiding risky left turns, the diverging diamond pattern reroutes traffic approaching to the left, creating uninterrupted access to the highway.
Since ground broke on the first diverging diamond interchange in Versailles, France, transportation officials have heralded the sleek interchange as an innovation in traffic control.
“What is significant about it and what makes it a really intriguing solution to traffic volume problems is that it will eliminate all left turns,” said Lou Hatter, a Virginia Department of Transportation spokesman.
According to Popular Science, which named the diverging diamond interchange the “Best of What's New 2009,” experts say the traffic pattern can reduce clogging by up to 60 percent.
“Think of it as a one-way street,” Popular Science’s tribute to the traffic pattern reads. “Drivers who want to turn left onto the highway can do so without crossing oncoming traffic. Through-traffic, meanwhile, stays on the left side of the road until it reaches a second stoplight, where it passes back over to the right.”
To date, only five diverging diamonds have been constructed in the United States, according to the Federal Highway Administration.
In June 2009, the Missouri Department of Transportation became the first state agency to embrace the new design with a project at the intersection of the well-traveled Kansas City Expressway and Interstate 44 in Springfield, according to the highway administration.
In a survey commissioned by MoDOT, more than 95 percent of respondents said the project made travel safer, more convenient and less congested. Almost 90 percent said that MoDOT made the right decision implementing the diverging diamond in Springfield.
Since Springfield, diverging diamond projects have been proposed in localities across the country, from Utah to Georgia.
The innovation has been heralded as a boon for road engineers looking to relieve congestion along highways where urbanization often leads to snarled traffic.
Since the early 2000s, the intersection of U.S. 15 and I-64 has funneled unprecedented growth into Zion Crossroads: Lowe’s, a Wal-Mart store and distribution facility, the Spring Creek Sports Club, a branch of the University of Virginia Community Credit Union, the Zion Crossroads Dental Office and others have set down roots in the once-quiet unincorporated community.
A UVa dialysis center treats about 55 patients three times a week on Circle Pointe Drive, less than a mile from the intersection, said Debbie Cote, a UVa Health System manager.
“Traffic out there, especially the tractor-trailer traffic, is almost impossible because of the growth and the businesses out there with Wal-Mart and Lowe’s,” Cote said. “You could sit through the left-turn light two or three times because it’s backed up with people in the left-turn lane.”
Removing the left-turn lane altogether would alleviate traffic and increase access to UVa’s facilities and the numerous businesses on either side of the interstate, Cote said.
“Oh my God, yes,” exclaimed Crystal Ford, a secretary at Kenny’s Auto and Quality Muffler. “Since the Wal-Mart and stores have come in, it’s really gotten hectic.”
For businesses such as Kenny’s, a lion’s share of their income is generated from people traveling along the interstate.
More motorists, more money.
“We have our regulars, but we do have a lot that come off 64 that might stop at the gas stations and have problems and get towed in,” Ford said. “I think this’ll help.”
“It’ll even out the truck traffic and definitely cut down on the backlog,” Cote said. “It will help patients get to the center and home in a simpler manner.”
VDOT estimates the interchange could be finished as soon as April 2014.
The design also is cheaper than the traditional alternative, a cloverleaf interchange. The diamond interchange contract is valued at $6.8 million, while a cloverleaf would cost $40 million and take longer to build, Hatter said.
Whereas a cloverleaf would require the state to construct new roads, the diverging diamond will allow construction crews to retain the current bridges and a large portion of the existing infrastructure, Hatter said.
“The only difference involved is we’ll mostly change the pavement where the two roads cross,” Hatter said.
For more info
Visit www.virginiadot.org/projects/culpeper/zioncrossroads.asp to learn more about the project and view a 3-D rendering.