Flexibility in Design Standards Examples Urban Arterial Standards  Design speed: 30-60 mph  Lane width: 10-12 ft  Shoulder width: 4-8 ft  # of lanes: 4-8 Rural Arterial Standards  Design speed: 40-75 mph  Traveled-way width: 22-24 ft (total for 2 lanes)  Shoulder width: 4-8 ft  # of lanes: 2 or more