Rocky Road. Workers placed 3,5000 boulders by hand to create a rough surface treatment.
(Photo courtesy of V3 Construction Group)

This fall, some suburban tire-kickers will roll off car dealers’ lots and onto what is believed to be the nation’s first public performance track. If the concept is successful, it may launch a niche for civil engineers.

Since construction began in April on the one-third-mile track in Naperville, Ill., builders have struggled with an unusual road design, says Bob Kozurek, city engineering manager. Engineers, too, “had nothing to go on,” says John O’Neill, project manager and civil engineering director for A. Epstein and Sons International Inc., Chicago. The city consultant hired Paxton Waters, a Carmel, Ind.-based architect who designs racetracks, to create the layout. Click here to view diagram

The $3.9-million project emerged as a public proving ground after residents complained that auto test-drivers were congesting local roads. The track will allow drivers to try things “they can’t really test drive on the street,” Kozurek says. For example, drivers will use a wet “skid” pad to deploy anti-lock brakes without risking an accident. And SUV enthusiasts will go “off-roading” by climbing up a miniature hill and bouncing down a short boulder run. The suburban Chicago facility will open Oct. 7.

So far, 12 dealers have agreed to pay assessments to a public-private cooperative in exchange for using the track. “The customers aren’t going to be charged any fee,” Kozurek says. Only authorized salespeople will have access, and drivers will sign liability waivers before entering.

Safety drove the design. Waters says the layout discourages risky maneuvers by having chicanes, or curves, that force drivers “to turn quickly but with a low speed.” Video cameras with a live Internet feed will keep a close watch. The cooperative plans to rent out the track for private events and use it to train police officers and other emergency personnel.

Building the track is “outside of the typical,” says Andrew Pizza, senior project manager for general contractor V3 Construction Group, Woodridge, Ill. The two-lane, rectangular course sits on a 9-acre site that formerly was a rail yard. The city acquired it for $2 million and started design in spring 2004. Work is set to wrap at the end of this month.

Inside the main loop is a 2-acre SUV course with three concrete pads designed to simulate off-road scenarios without the constant maintenance. The first is a banked pavement with an 8% cross slope. It progresses into a 12-ft-tall hill paved with exposed aggregate. The final touch is a 150-ft-long “rough road” peppered with boulders that protrude 3 to 6 in.

Laying the flat skid pad tested asphalt workers, who usually add slopes for drainage. But on this surface “you want to hold water on it,” Pizza says. Nearby spray heads will irrigate it.

In the SUV area, estimators accounted for displacement of the 12-in.-thick rough road by having workers pour a 10-in. concrete pad. The surface rose 2 in. after they pushed in 3,500 boulders.

The track is generating “a lot of excitement,” Kozurek says. Foremen have a hard time keeping workers off it. Designers plan to take a few laps, too, although O’Neill has mixed feelings about the rough road. “I don’t think my Taurus could handle it,” he says.