If Forest Park Parkway is your favorite route to work or school, you're about to get some company.

Traffic on the parkway increased by 30 percent during the first Highway 40 closure, and with the next closure later this month, traffic officials anticipate a steady growth in popularity.

"Anybody who thinks it's a secret route, they're mistaken," said Garry Earls, chief operating officer for St. Louis County. "It's not a secret."

Running roughly parallel to Highway 40 (Interstate 64) with two lanes in each direction, Forest Park Parkway is expected to see traffic levels double at times, compared to today. The expressway carries 14,000 to 23,000 cars a day right now.

It's not the official detour. Missouri highway officials are encouraging eastbound motorists to take Highway 40 to northbound I-170 to eastbound I-70 to bypass the work zone. Westbound drivers should take 70 to 170 south to westbound 40.

But the Missouri Department of Transportation made it easier for those who do choose Forest Park Parkway, extending the exit lanes on Interstate 170. Traffic signals are being coordinated on the parkway to accommodate the flow of cars.

"One of the primary things we are working on along with the city is to make sure the timing of lights and signals along there are coordinated so the flow of traffic can be eased in that corridor," said Sheryl Hodges, director of St. Louis County's Department of Highways and Traffic.

When the closure shifts to the four-plus miles just east of I-170, the county will monitor travel times and keep an eye out for bottlenecks, Hodges said.

"We think that Forest Park Parkway will probably be how Clayton Road was this time," said Linda Wilson, a MoDOT spokeswoman. "Clayton and Ladue (Road) were not our suggested alternate routes this year, but we knew they would be heavily used because they were closest to the closed section of the highway."

Traffic planners say commuters can make their lives easier by driving during off-peak hours, car-pooling or hopping on MetroLink or a bus.

Judy Chapman, who lives in the Central West End and drives on the parkway four to six times a day, said she expects it to get a whole lot busier. Chapman wants to see the lights timed better, particularly those at DeBaliviere Avenue, Des Peres Avenue and Skinker.

"I am not even going to attempt it, frankly," she said. "The lights are so badly timed, I get frustrated."

Traffic hassles are nothing new to people who travel this part of the region.

Much of Forest Park Parkway itself was closed for nearly three years to build the $676 million MetroLink extension stretching from Forest Park to Clayton and then to Shrewsbury. It reopened in the middle of 2006.

kleiser@post-dispatch.com | 314-340-8215