Pay as you go

An unfortunately damaged mileage marker on the trackbed of the old railway line linking Fraserburgh with Aberdeen
 It dates from the time when rail fares were charged by the mile. Mile posts were situated every quarter mile along the track - they indicated the distance to the main terminus of the line,  in this case Aberdeen which was 54 miles from this point. The dots indicated quarter miles. The posts enabled passengers to check that they were being charged the correct fare .  
Much simpler than the complexity of ticketing today.