Intelligent Interstate

Originally envisioned as a normal highway to ease traffic congestion on Interstate 81 between Blacksburg and Roanoke, Virginia's Smart Road evolved into something much more.

And until traffic volumes on I-81 reach their peak in about 20 years, it is in use solely as a sophisticated test track here near the campus of Virginia Tech University, booked regularly by various automotive companies and government and private research organizations to test for myriad transportation-related issues.

It can be used to evaluate vehicles on a variety of pavement conditions and is the only U.S. test track that can create multiple weather conditions, including rain, fog and snow, thanks to a half-million-gallon (1.8 million-L) water tank.

Other features include overhead lighting and traffic signals. Fiber-optic cable runs along the road for the transmission of data, and about 400 sensors are buried in the layers of asphalt that are wired to underground bunkers.

The Smart Road, a joint project of the Virginia Dept. of Transportation (VDOT), Federal Highway Admin. and Virginia Tech's Transportation Institute (VTTI), first came to be in the late 1980s and early 1990s, as state government officials recognized the need in the future for a connector between Roanoke, a well-populated city, and the smaller town of Blacksburg. The “smart” part of the road came later as government leaders recognized a need for transportation research.

Groundbreaking in Montgomery County took place in July 1997, and the first 1.7-mile (2.7 km), 2-lane stretch was completed in December 1999, with a bridge added in 2002 to bring the track's total length to 2.2 miles (3.5 km).

Originally, one of the touted features was the ability for vehicles to drive themselves by communicating with magnetic sensors embedded in the roadway.

Dave Clark, assistant research engineer for VDOT, says that idea never really caught on, and right now, “there just isn't much interest in that kind of research.” Clark says people might have seen a similar experimental stretch of Interstate 15 in San Diego (now currently in use as high-occupancy vehicle lanes) and the notion of having a car that drove itself scared them.

“But we weren't leaning everything on that,” he says of the autonomous auto ability. Sensors were embedded, nonetheless, in case anyone wanted to test self-driving cars.

Clark estimates the cost of building the Smart Road and a nearby bridge at $50 million, with the government footing 80% of the bill, and private funds contributing the remaining 20%.

He says the project has been profitable when the cost of constructing the road is factored out, as VDOT figures the road would have been built anyway. The amount of money spent equipping Smart Road with a plethora of technology likely has been recouped, says Clark. Testing is done almost every day and night, except for the wintertime, when the pace slows.

Often, companies or organizations using Smart Road remain anonymous to protect experimental technology or research testing that may be taking place.

“A lot of times they don't even want you to know which (companies are testing),” says Clark. “You look at the schedule and it doesn't say, ‘GM testing today,’ it says ‘M.A.C., for major automotive company.’ That's all they'll tell you.”

General Motors Corp. has a long-term contract to use Smart Road for testing and evaluated driver distraction in regards to in-vehicle infotainment systems for its Cadillac CTS here.

The eventual plan is to make Smart Road a 4-lane, 5.7-mile (9.1-km) stretch that will be open to normal traffic, but Clark says there is no set date for completing the remaining 3 miles (4.8 km) due to a budget crunch in the state of Virginia, as well as more pressing traffic concerns in the northern Virginia/Washington D.C. area.

Original traffic projections pegged the need for a 2-lane stretch by 2010 to ease congestion on I-81, which is expected to reach capacity by 2020. When, and if, the road is open to public traffic, Clark says testing will have to be curtailed some, with most of it likely having to take place at night, during non-peak hours or on select lanes.