I do not think the traffic is all that bad especially if you are from the east coast, like I am That said, when you cross the river into St Louis I would advise you stay in middle lane or left lane. I stay in the left lane. The reason is many cars are exiting to the right to get onto I 44/55. ( I am refering to the Poplar Bridge which I believe is the main one people use) The mlk bridge is real easy but takes you to I 70
Just read your post after I posted If you going south you wish to take 255 south A bit longer but no traffic at all At least in the 12 yrs I have lived here