¹ Semitrailers up to 53 feet may also operate without a permit by conforming to a kingpin-to-rearmost axle distance of 38 feet. Semitrailers that are consistent with 23 CFR 658.13(g) may operate without a permit provided the distance from the kingpin to the center of the rear axle is 46 feet or less.

² Semitrailers up to 53 feet in length may operate without a permit by conforming to a kingpin-to-rearmost axle distance of 40 feet 6 inches. Semitrailers that are consistent with 23 CFR 658.13(g) may operate without a permit provided the distance from the kingpin to the center of the rear axle is 46 feet or less.

³ Semitrailers up to 53 feet in length may operate without a permit by conforming to a kingpin-to-rear axle distance of 41 feet, measured to the center of the rear tandem assembly. Semitrailers that are consistent with 23 CFR 658.13(g) may operate without a permit provided the distance from the kingpin to the center of the rear axle is 46 feet or less.