When the rebuilt section of Highway 40 reopened ahead of schedule last December, Branden Gary, like many motorists, assumed that construction west of Interstate 170 was over.

But then crews started closing lanes again. Sound walls weren't finished, and those that were up needed to be stained. Work continued on roads under or over the highway — such as Lindbergh and Brentwood boulevards. And now crews are closing lanes nightly on the reopened section to restripe the highway.

"They open it, and then close it," said Gary, of Clayton, outside Schnucks on Clayton Road on Friday. "It's kind of a hassle."

In the Highway 40 (Interstate 64) rebuilding job, hitting deadline and fully completing the road work are two separate things. The contract between Gateway Constructors and the Missouri Department of Transportation required that lanes west of I-170 to reopen by Dec. 31, 2008, and that the stretch between I-170 and Kingshighway reopen by Dec. 31 of this year.

The contract promises Gateway $2 million in incentive pay for making or beating each of the deadlines. Failing to reopen the highway on time would cost Gateway $24,300 a day every day starting Jan. 1, 2010, until lanes are open, according to the contract.

But the document does not require that all aspects of the highway project be finished the moment traffic starts flowing. Work on final details may continue until July 31, 2010.

"I'm sure there's still going to be some sound-wall work after the main line opens up," said Paula Hughes, spokeswoman for Gateway Constructors. Some landscaping, striping and other details on overpasses will be left to finish as well, she added.

The contract also sets time limits as to how many days full closures are allowed on some overpasses, such as Hampton Avenue and Bellevue Avenue over Highway 40. Big Bend Boulevard, for example, can be closed no longer than 180 days. The same is true for Hanley Road, which can be closed no longer than eight months. It's scheduled to reopen July 31, one month early. Some overpass work isn't required to wrap up by Dec. 31. Finishing the Clayton Avenue overpass in Dogtown, for instance, does not affect reopening the highway, so it could continue into next year. However, Gateway officials say they aim to complete it by the end of the year anyway. The Clayton overpass is set to come down Aug. 3, the same day the Oakland Avenue overpass reopens.

Landscaping work — from shrub planting to erosion control — also is expected to continue into next year. And even if sound walls are up, they might not all be stained, as was the case with the western half.

"All of those things aren't critical to getting the lanes open," said Linda Wilson, spokeswoman for MoDOT. "The bonus is only tied to reopening the highway. It isn't completion. It's getting the highway open to 150,000 cars a day."

Soon after lanes west of I-170 reopened on Dec. 15, crews began occasional closures to finish installing sound walls. The manufacturer couldn't keep up with production last year, so installation fell behind. The final sound wall panel was installed at Clayton and Warson roads last week.

Pavement work at the McKnight Road overpass at Highway 40 finished earlier this month.

Stripes painted late in the year began to wear off in the spring because they were put down during cold weather last year. For paint to stick longer, it must go down on dry pavement when temperatures are 50 degrees or warmer, Hughes said. Crews were putting down permanent stripes on the westbound side this week.

A few heavy rains this summer produced erosion problems that required landscaping crews to repair slopes and ditches. Work behind sound walls — mostly grading — is ongoing.

The ongoing work hasn't bothered Michelle Hill of Maplewood, whose routine as a nursing assistant has been disrupted with the current shutdown.

"I'd rather it be partially open than not open at all," she said.

Motorists should expect the same types of highway tinkering for the eastern half of Highway 40 next year.

However, closing lanes on the highway and on entrance and exit ramps will be limited.

"It will be more at our discretion if they need to close any lanes, when those lanes will close," Wilson said.

So far, traffic volumes between I-170 and Ballas Road are just 40 to 80 percent — depending on time of day — of what they were before that section of the highway closed in January 2008, according to MoDOT. Crews have had more leeway in closing lanes because traffic is light, Wilson said.

Traffic is expected to return to previous volumes once the closed section reopens and motorists have all of Highway 40 back. If this holds true, Gateway crews will have a tougher time closing lanes and wrapping up unfinished work.

"If they need to do anything, their times will be limited to at night or the middle of the day," Wilson said.