The predicted traffic mix of a proposed four-lane urban non-interstate freeway: Passenger cars = 69% Single-unit trucks (two single axles): 2-axle, 5000 lb/axle = 20% 2-axle, 9000 lb/axle = 5% Single trailer trucks (three single axles): 3-axle, 23,000 lb/axle = 4% 3-axle 20,000 lb/axle = 2%