In today's "Ask the Road Crew" column in the Post-Dispatch a reader asked this: "Heading east from Clayton Road at Skinker Boulevard onto the eastbound 64/40 ramp in the right lane, on several occasions I've almost been hit because people in the left lane lose track of where they are supposed to be. This is rather dangerous, and stripe guidelines are desperately needed here."
Ok, first of all I agree about the striping. As far as I can tell there isn't any and that entrance ramp onto the highway merges into one lane and that lane is the left lane. So striping would help. However, the writer of this question who claims to use that ramp many times should know by now that it's much better to be in the left lane right from the start. It's not the left lane drivers who lose track, it's mostly people who don't seem to realize the right lane ends they have to merge left and they wait until the last minute.
I get on 64/40 at that point all the time and see right lane people almost have to stop because they can't get over in time. Much of this is due to a rather short green light for drivers on Clayton Road heading east to the on ramp. I've studied this endless times as I watch drivers at other points at that intersection get a long green light while the eastbound's is very short comparatively. So in order to at least try to get onto the ramp with a green light, many drivers use the right lane.
If you're going north/south or west onto Clayton from the highway you'll have a fairly long green light. I never understood why the eastbound light is so much shorter and with traffic at various times of day backed up to past the Cheshire, it makes no sense. That is why the merge into the left lane gets troublesome.
If nothing else I guess some lane lines painted would help, but giving more green light time for that direction would be even better.
As an aside, I can never find the "Ask the Road Crew" linked on the P-D's website. The most recent column I've found is from 2017.