|FAST LANE Barrier preps Lake Shore Drive for rush hour. (Photo courtesy of Chicago Dept. of Transportation)|
For the first time, Chicagos Dept. of Transportation has found a unique way to manipulate highway workzone space while also attempting to improve traffic flow for drivers outside the lines. Pleased with a device called a "moveable barrier," or "zipper wall," on its current restoration of South Lake Shore Drive, CDOT is using it again as it rebuilds the Chicago Skyway, a congested 7.8-mile-long overpass that connects drivers to the south of the city to and from Indiana.
Zipper-walls exist for temporary and permanent installations, allowing users to lift and shift several lane miles of concrete barricade in approximately one hour or less. Although the 18-year-old technology began to attract attention 10 years ago, its expensive cost and specialized application restricted it to high-profile, urban highway projects (ENR 3/2/92 p. 36). That still has not changed.
Nevertheless, Chicago transportation officials now are finding it to be "an important part of helping to manage traffic during peak construction," says Chris Wuellner, project manager for South Lake Shore Drives $162-million rehabilitation. The Lake Shore Drive project began in 2001 and is scheduled to finish in 2004.
In late June, CDOT removed the 16,000-ft-long barrier from Lake Shore Drive and is now moving into final roadwork stages. Meanwhile, the department has placed another 13,000-ft-long barrier on Chicagos Skyway for its $250-million renovation, expected to be completed in 2005.
Barrier Systems Inc., Rio Vista, Calif., builds and leases the reversible-lane devices, which consist of concrete segments of indefinite length and a 1,500-lb, hydrostatically powered transfer vehicle traveling at 5 mph. Chicago-based, minority-owned Riteway Construction Services operated and maintained the barrier on Lake Shore Drive, costing CDOT $665,000. The firm also is handling the Skyways barrier. Those costs are contained within a separate $14-million, three-year contract.