Ridden horses, like pedestrians, were there first! Anything or anyone that comes along later should design their machine, road use, and behaviour around what was already in existence.
Apart from the minuscule amount of truly new roads, (i.e. new routes not just upgrading of old routes), we owe pedestrians, horse riders, and carriage drivers a great debt for forging thousands of miles of what we now enjoy as 'CARRIAGEWAYS!. The only thing that the motor generation are responsible for are Motor ways