Here is a picture of Tommy Milton in 1923 in the cock pit of a Miller special.
Although motorcycles were a big attraction these tracks were primarily built for cars from as early as 1910 with some tracks still in operation into the late 20's.
Venice California called Playa-Del-Rey 1 mile long, Elmhurst Ca had one .5 miles long called Oakland, Omaha Nebraska had one 1.25 miles long, Brooklyn N.Y. had a 2 mile track called Sheepshead bay, Beverly Hills had a 1.25 long track, Fresno had a 1.0 mile track, Cotati Ca had one 1.25 long, San Carlos Ca had one 1.25 long, Tipton Pa had one called Altoona that was 1.25 long, Culver City Ca had a 1.25 mile long track all in all there were 24 tracks scattered around all made with 2x4's on edge and some of the banked corners were 60 degree's. Local fire departments would spray them down with water before the race to swell up the cracks.
A month after his Indy 500 win This is a Monroe-Frontenac, Gaston Chevrolet with Johnny Bresnahan at the wheel