Years ago, I drove the original EEC from St Louis to Pittsburgh (except for the bike paths of course) while on the way to visit a relative. To me, there were numerous parts of that had serious traffic issues in each state, the worst being between Terre Haute to Martinsville, IN, and Westerville, OH to Follansbee, WV. Basically, the issue with those areas are a combination of high traffic counts, no shoulders, and/or short sight lines.
As a result, I created my own EEC (
https://ridewithgps.com/collections/1838432 ). When I rode the main route in September of 2023, it was fine with only a few short sections of heavier traffic (maybe 10 miles total). Carla Majernik, the previous ACA Routes & Mapping Director before she retired, even called me for some section updates as ACA had received several reports of traffic issues on those sections mentioned above. So I drove the route the official route from Pittsburgh to Tierra Haute on my way home from the end of my tour and the traffic was even worse. Unfortunately, she retired before she could implement any changes though I think she was interested in those two sections most.
Additionally, if you can ride some gravel, north of Terre Haute is an alternate route that includes over a dozen covered bridges (I love them).
I am in the process of updating all the routes onto RWGPS but have all the data including a lot of services (campgrounds, hotels, grocery, etc.) on GPX files if you need them. There typically is camping available and if not, hotels, so no stealth/wild camping is required.
I especially enjoyed the section from Westerville, OH, to Steubenville as it went through a lot of Amish country. Unfortunately, the bridge crossing at Steubenville closed last year (indefinitely due to structural issues). As a result, I recently re-routed the section between between Bloomingdale, OH, and Follansbee so I have not ridden that portion. This re-route looks good (but hilly) on paper except for a ~3 mile section with heavy traffic (12k AADT) with minimal shoulder and rumble strips though the route has 4 lanes in that section.
Regarding other portions of the official ECC, I would go off route and use the rail trails between Boonville, MO, and Kansas City. Here (
https://ridewithgps.com/collections/57717 ) is another collection to help you get between Boonville and Platte City where you can reconnect with the ECC and/or Lewis & Clark Route. I agree with Jamawani/John that US-36 is not the best. Years ago, probably a dozen or more, I rode from Lindsborg, KS, (see collection above to get from KC to Lindsborg) to Fort Collins. VERY roughly, the route goes diagonally up toward Franklin, NE, then westwardly mostly following US-34. At the time, traffic was fine overall and usually had a shoulder if traffic increased. However, I do not know the current AADT or conditions. I have those GPX files also if you want them.
Whatever you choose to do, have a great tour!
Tailwinds, John