Question: what is the standard width of a lane?
Answer: The Interstate Highway standards for the U.S. Interstate Highway System use a 12-foot (3.7 m) standard lane width, while narrower lanes are used on lower classification roads. In Europe, laws and road widths vary by country; the minimum widths of lanes are generally between 2.5 to 3.25 metres (8 ft 2 in to 10 ft 8 in).