Construction on the 11.5-mile stretch between Tower Grove Avenue in St. Louis and Spoede Road in west St. Louis County is expected to begin in 2003 and last seven to 10 years.
Highlights of the plan to improve Highway 40 (Interstate 64) include additional lanes and a new interchange at I-170, as well as the replacement of every bridge structure along the route. Highway engineers plan to control congestion using high-tech "intelligent" transportation systems such as ramp signals, electronic congestion detectors and overhead message boards.
The highway was built in the 1940s and '50s and is falling apart. Some bridges are too low to provide enough clearance for trucks. Interchanges are notorious for tight cloverleafs and short merge lanes.
A 3.5-inch layer of pavement will be laid down this year to buy time until reconstruction can begin.