Purpose And Application Of This Chapter

(1) Purpose. The purpose of this chapter is to prescribe rules in the interest of public safety and preservation of highways, for the issuance of special permits for the transportation of such overweight or overdimensional articles or commodities as cannot be reasonably dismantled or conveniently transported otherwise, and for the operation of such overweight or overdimensional vehicles, motor trucks, semi-trailers and trailers, whose gross weight, including load, or whose height, width, or length, may exceed statutory limits, or which in other respects fail to comply with requirements of T.C.A. §§ 55-7-201–203, as may be reasonably necessary for the transportation of such overweight or overdimensional articles or commodities as cannot be reasonably dismantled or conveniently transported otherwise. (2) Application. These rules apply to, and a special permit issued by the Tennessee Department of Transportation (hereinafter also referred to as “TDOT” or “Department”) shall be required for, the operation of any motor vehicle on the state highway system, including the interstate highway system, whenever the motor vehicle, including the load, exceeds any of the following size and weight limits established by law: (a) General Size and Weight Limitations Established in T.C.A. §§ 55-7-201–203: OVERWEIGHT AND OVERDIMENSIONAL MOVEMENTS CHAPTER 1680-07-01 ON TENNESSEE HIGHWAYS 1. Gross weight: 80,000 pounds, except that freight motor vehicles operating on the interstate highway system shall not exceed the lesser of 80,000 pounds or the weight produced by application of the formula set forth in T.C.A. § 55-7-203(b)(3). 2. Single axle: 20,000 pounds, except as provided above. 3. Tandem axle: 34,000 pounds, except as provided above. 4. Width: 8 feet 6 inches. 5. Height: 13 feet 6 inches. 6. Length: (i) Straight truck: 45 feet. (ii) Straight truck with trailer attached: 65 feet. (iii) Truck tractor and semi-trailer or trailer combination: The towed vehicle shall not exceed 50 feet in length from the point of attachment to the tractor; provided, however, if the towed vehicle exceeds 48 feet in length from the point of attachment to the tractor, the distance between the kingpin and the rearmost axle or a point midway between the two rear axles, if the two rear axles are a tandem axle, shall not exceed 41 feet; and (I) Except, if transporting livestock or automobiles and/or motor vehicles: 52 feet in length from the point of attachment to the tractor; or (II) If transporting poles, logs, or timber in single length pieces: 75 feet total length. (iv) Truck tractor and twin trailer combination: 28 feet 6 inches either towed vehicle. (b) Exceptions under State Law: Exceptions to the general size and weight limitations described in subparagraph (a) are authorized in T.C.A. § 55-7-115 and T.C.A. §§ 55-7- 201–205, including without limitation exceptions for vehicles used exclusively to transport cotton seed modules (see Rule 1680-07-01-.08) and an exception to length limitations for any vehicle disabled on a highway and being towed to a repair or terminal facility within one hundred (100) miles (see Rule 1680-07-01-.19). Movements made in compliance with these exceptions are not subject to the special permit requirements established in this chapter. (c) Exceptions under Federal Law: Additional exceptions to the general size and weight limitations described in subparagraph (a) above are required under federal law, OVERWEIGHT AND OVERDIMENSIONAL MOVEMENTS CHAPTER 1680-07-01 ON TENNESSEE HIGHWAYS including 23 U.S.C. § 127 and 49 U.S.C. § 31111, and including without limitation exceptions from weight limits on the interstate highway system for heavy duty tow and recovery vehicles and emergency fire suppression vehicles, as incorporated into T.C.A. § 55-7-203. Movements made in compliance with these exceptions are not subject to the special permit requirements established in this chapter.