Automobiles will be cheaper than horses.

John Elfreth Watkins : engineer
Farmers will own automobile hay-wagons, automobile truck-wagons, plows, haroows and hay-rakes. A one pound motor in one of these vehicles will do the work of a pair of horses or more. Children will ride in automobile sleighs in winter. Automobiles will have been substituted for every horse vehicle now known. There will be, as already exist to-day, automobile hearses, automobile police patrols, automobile ambulances, automobile street sweepers. The horse in harness will be as scarce, if, indeed, not even scareer, then as the yoked ox is today.

Tom Geoghegan. "Ten 100-year predictions that came true", BBC News Magazine. 11 Jan 2012.