I found this one kind of interesting. Highways are extremely important in this day and age, but as you know, they were not always there. On this date in 1940, the Arroyo Seco Parkway was dedicated in California. It was the first completed highway in the Western U.S., and it is the oldest one in service.
Before becoming a modern highway system, Arroyo Seco Parkway was a wagon trail, and then a bike/auto roadway. As this was developed, off-ramps were placed at ninety degree angles, and that was no problem when high speeds were 45 MPH. Buses and trucks were not allowed on this road, and it averaged 27,000 vehicles per day. Today, it averages 122,000 vehicles per day, and it still remains very much like it was back then. There are no banked ramps, and there are no acceleration/deceleration lanes. I had no idea something like this existed.