I-90, UNITED STATES-- 4,991 K Longest U.S. interstate.
PAN-AMERICAN HIGHWAY, 18 COUNTRIES-- 47,958 K. Prudhoe Bay, Alaska to Ushuawa, Argentina.
401 MacDONALD CARTIER FREEWAY, CANADA-- 818 K. Toronto and is the busiest highway in North America as well as one of the widest as well.
ROUTE 6, GAR HIGHWAY, UNITED STATES-- 5,158 K. Named for the the Civil War Union veterans association, the Grand Army of the Republic. Goes through 14 states.
HIGHWAY 1, AUSTRALIA-- 14,500 K. Covers most every inhabited part of Australia. More than one million travel some stretch of it every day.