Linda Wilson of MoDOT and Dan Galvin of Gateway Constructors hold 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:

ken: I've noticed access to I-64 has been completely removed from Oakland Avenue. Why, and what's the alternative?

Linda Wilson: The access at Oakland has been removed. You still have the bridge crossing over I-64, but no ramps on and off the highway. They were too close to the McCausland on- and off ramps. Your alternatives would be the McCausland interchange to Oakland or the Hampton interchange to Oakland.

Russell Groener: I was surprised that the new section of I-64 from Ballas to 170 does not have reflective markings (cats' eyes) to delineate lanes at night or in bad weather. Can you tell me why these were not put on the highway? Will the section from I-170 to Kingshighway have them?

Linda Wilson: We do not use the raised pavement markers anymore. They are a problem for our snowplows and they tend to get knocked out quickly. The new technology that is used on I-64 is a reflective tape. This is the latest standard for improved pavement markings.

Steve: After the I-64 Project is completed, what steps will be taken to keep people from putting graffiti on the walls of pedestrian tunnels, etc.? Will cameras be used, such as the ones at the MetroLink stops? After spending $500 million, it would be nice to keep the new construction graffiti-free.

Linda Wilson: We do not have cameras in the tunnels. We hope citizens will be respectful. If you see someone putting graffiti on the walls, please call 911 so they can be caught and prosecuted. We do have a stain to cover any graffiti that is put up.

gregl: What mainline paving remains to be done at this point?

Dan Galvin: Not much. The final pour for the big paver (25-feet wide) is going on right now between Oakland and McCausland. We will still have a few single lanes, shoulders, ramps and barriers to complete after that, but the mainline itself is nearly complete.