Join Linda Wilson of MoDOT and Dan Galvin of Gateway Constructors an online chat each Wednesday about Highway 40 (Interstate 64) construction and other highway issues. Submit questions at STLtoday.com/discussions. Here is an excerpt from last week:

DogEatDog: Clayton/Warson: Where Clayton Road runs over a creek under I-64 looks pretty rough, especially the sidewalks. Does the city of Ladue have any plans for this?

Linda Wilson: Yes. The city of Ladue has a project to replace the old bridge and that includes the sidewalks. I think the work is scheduled for 2010. They didn't want to do this while I-64 has been under construction because Clayton Road has been such an important alternate road.

Mark: What is the plan to ensure that equipment, signs, etc., won't be left behind when the remaining section opens?

Dan Galvin: We always do a final "safe to open" walk-through with MoDOT before we open anything to traffic. If, during this walk-through, we discover that we've left a paving machine in the middle of the highway, you can be sure we'll move it out of the way.

julianjacquin: I'm looking at buying a new house, and I've found a few in Brentwood and Ladue that I'm interested in that are somewhat close to 40. I wanted to know whether, since reopening the western portion of 40, there have been any noise complaints along the interstate behind the sound barriers? Particularly around McCutcheon/McKnight. I notice the sound barriers are pretty high, but I was wondering how loud it still is on the residential side.

Dan Galvin: The sound walls were designed to reduce traffic noise by at least five decibels at the homes nearest to them. The people across the street from the homes with the sound walls probably won't really notice much of a difference, as the traffic noise will spread throughout the neighborhood as background noise. The closer you are to the wall the more benefit you receive from it. But you will always be able to hear traffic noise if you live near a freeway.