St. Louis? ... Not sure... Driving i ended up taking hwy 63 in Missouri, into Arkansas (fabulous NEAT antique shop... ), 63 through Arkansas to Memphis... @ Memphis i got the i55 straight down to nearly Nola...
The 55 runs south outta st. louis... Mississippi has GORGEOUS rest stops on the 55... I didn't have a problem crashing at em, nor flying a sign ... Stayed 2 nights (long state & nearly the end, long drive)
I'd say just hit the 55 ... But I was in a hurry... So, not exactly taking the scenic tours anymore.