The bonanza of abandoned old pavement along the Illinois National Road dries up just before Montrose, a little town just east of Effingham. Thence west, US 40 almost entirely follows the same alignment of the road from when Illinois paved it in concrete in the 1920s. From a postcard, here’s what that concrete looked like when it was new.
Almost all of that road is covered with asphalt today – almost. A little of this concrete is visible where US 40 and I-70 intersect east of Vandalia. This remarkable confluence of roads includes not only the original US 40 alignment, but a newer alignment of US 40 that bypassed Vandalia. Much of that bypass later became I-70.
This 1920s concrete road was built 18 feet wide, where the old abandoned brick and concrete road well east of here was just 16 feet wide. But in this photo you can see concrete strips added on either side to widen it by a few extra feet. Notice also that the original middle portion of the road has no expansion joints, and so it cracked. The 1920s was a time of learning in roadbuilding, and later concrete roads all had expansion joints. This is an eastbound photo from the east end of the concrete alignment.
I turned around in the same place to take this westbound photo. Notice the curved strip added on the north side of the road to let traffic flow into the later alignment of US 40, which bears right. The concrete alignment picks up dead ahead.
What an awkward intersection these two old roads must have created when they were still in use.
Here’s an eastbound photo of where the original US 40 alignment ends at I-70.
I’ve seen topographic maps from 1969 and 1977 of this area. In the 1969 map, I-70 was nowhere in sight. In the 1977 map, this entire configuration existed. So the old concrete road was in use through sometime during the 1970s, and the time when I-70 merged onto US 40 here lasted a few years at most.