1898-1935 was a trasistion period, and testing time for the different methods of transportation when it wasn't clear what was going to be the winner in the auto wars. This was a time when some still used horses, pedal bikes were getting a lot of sales, motorbikes were really making progress, and yet steam power wasn't out of consideration for some more industrial applications. Tractors were generally huge expensive things that most family farms wouldn't be able to afford unitl the 40's and 50's... and trains were mostly steam until the 50's.http://www.darkroastedblend.com/2007/12/steam-buses-trucks.html
Strange and varied time in the US transportation industry, my other post about the great depression dooming most of the independants is a good bit to read for more if you like to learn this kind of stuff like I do.
http://justacarguy.blogspot.com/2007/07/interesting-thoughts-on-automobiles.html#links
http://justacarguy.blogspot.com/2007/07/changing-times-in-auto-industry.html#links
http://justacarguy.blogspot.com/2007/07/how-cadillac-was-only-profitable-auto.html#links
http://justacarguy.blogspot.com/2007/07/prior-to-great-depression-there-were.html#links