We might also see horses replaced by motorcycles, perhaps even an erlier invention and adoption of dirtbikes and other cross crountry versions.
By 1914, the Model T cost less, and had better cross country performance than the Indian Motorcycle, that had suspension on both front and rear.
It could carry more load, and far easier to drive, and was all weather
This killed the US Motorcycle market, from over a dozen companies, to three.
The Motorcycle share the same problem as mounted troops, you really can't fight from them, you have to dismount.
So that leaves the job of some scouting and relaying messages