Four or six draught animals were needed to pull a coach and they had to be changed every 6 to 12 miles, depending on the condition of the roads. In England it was calculated that one horse was needed for every mile of a journey on a well-maintained turnpike road. So, for the 185 miles from Manchester to London, 185 horses had to be kept stabled and fed to deal with the seventeen changes required by the stagecoaches which traveled the route. Those horses in turn required an army of coachmen, postillions, guards, grooms, ostlers and stable-boys to keep them running. As a coach could carry no more than ten passengers, fares were correspondingly high and out of reach of the mass of the population. A journey from Augsburg to Innsbruck by stagecoach, although little more than 60 miles as the crow flies, would have cost an unskilled laborer more than a month’s wages just for the fare.
That is from new and excellent The Pursuit of Glory, Europe 1648-1815, by historian Tim Blanning. The best parts of this book — which are very good indeed — are the early sections on the economic history of transportation.
Here is a previous installment of The World We Have Lost.