The width of some of those streets is amazing. I heard that they were wide to allow a horse and wagon to turn around. Sure made it nice when they paved them and if it was a busy town, there would be room for 4 lanes and parking!
There are several small towns around here that was built along the Santa Fe and the Oregon trails. Their down town streets are brick and are wide enough for farmers to park their pickups in the center, cars along the store fronts and still plenty of room for vehicles driving through. Plus sidewalks.
Perhaps the main streets of the towns along the trails were sized big enough for a herd of cattle being driven through town?