Irreducible load permits are available if the vehicle exceeds the maximum width, height, or length. Permits issued by the Massachusetts Turnpike Authority (MTA) are not transferable to another vehicle. Upon application for an irreducible load permit, the applicant must demonstrate the number of work hours required to dismantle the load. MTA does not issue a special permit with respect to weight, and a vehicle may not use a way, if the vehicle exceeds the gross vehicle weight rating or the registered gross weight. Special hauling permits are required if the vehicle or combination exceeds the federal bridge formula weights or either of following:
| Type of Vehicle | Maximum Weight |
|---|---|
| Motor vehicle with 2 axles | 46,000 lb |
| Vehicle or combination with 3 axles | 73,000 lb |
| Vehicle or combination with 4 or more axles | 87,000 lb |
| Vehicle or combination with 5 or more axles | 99,000 lb |
| Axle Spacings | Maximum Weight |
|---|---|
| A single axle or axles spaced less than 6 ft apart | 18,000 lb |
| Axles spaced 6 ft or more apart | 22,400 lb |
A vehicle weighing more than the maximum vehicle weight specified above does not require an irreducible load permit for the use of the Ted Williams Tunnel, including the South Boston Bypass Road, provided that the Commissioner of Highways has issued an annual permit for construction equipment for the vehicle, allowing the vehicle to operate at a higher weight. An original annual permit issued for construction equipment must be kept in an accessible place in the vehicle to which it was issued and must be presented to an officer or MTA personnel upon demand.
| Way | Maximum Vehicle Height |
|---|---|
| Turnpike | 13 ft 6 in |
| Ted Williams Tunnel | 13 ft 6 in |
| Callahan Tunnel | 12 ft 6 in |
| Sumner Tunnel | 12 ft 6 in |
| Thomas P. O'Neill, Jr., Tunnel | 13 ft 6 in |
| Prudential Tunnel | 13 ft 6 in |
| CANA (City Square) Tunnels | 13 ft 6 in |
| Other way not listed above | 13 ft 6 in |
For use of the Tunnels, a permit is required if the vehicle length is greater than the maximum vehicle length in the table as follows, and in the case of a tandem unit operating on a way, in the note below:
| Type of Vehicle | Maximum Vehicle Length |
|---|---|
| 1 No overall length limitation applies to a semitrailer unit with a semitrailer up to 53 ft in length. | |
| 2 The vehicle length includes front and rear bumpers, but does not include a load overhang up to 3 ft beyond the foremost part of the front transporting vehicle or more than 4 ft beyond the rear bed of the rear vehicle. | |
| 3 A number of vehicles may be transported in combination by means of saddlemount combination or fullmount mechanism. | |
| 4 A tandem unit may operate on a way without a special permit with respect to its length, provided that the overall total number of semitrailers or trailers in the tandem unit is no greater than two; each semitrailer or trailer of the tandem unit does not exceed 28 ft in length, without regard to the overall length of the tandem unit; and a tandem unit with semitrailers or trailers that do not exceed 28 1 /2 ft in length, if such semitrailers or trailers were actually and lawfully operating on December 1, 1982, as part of tandem units within a 65 ft overall length limit in any state, may similarly operate on a way without a special permit with respect to its length. | |
| Motor vehicle not listed below | 33 ft |
| Vehicle combination other than semitrailer unit and not of a combination listed below | 60 ft 1 |
| Articulated bus | 60 ft |
| Auto home | 40 ft |
| Autotransporter (traditional) | 65 ft 2 |
| Autotransporter (stinger-steered) | 75 ft 2 |
| Boat transporter (traditional) | 65 ft 2 |
| Boat transporter (truck-trailer) | 65 ft 2 |
| Bus or school bus | 45 ft |
| House trailer | 40 ft |
| Saddlemount combination | 75 ft 3 |
| Semitrailer | 53 ft |
| Tandem unit | 4 |
| Trailer in a tractor-trailer combination | 53 ft |
| Trailer not in a tractor-trailer combination | 33 ft |
| Truck | 40 ft |
A permit is required if, for use of a way other than the Tunnels, the vehicle length is greater than 55 feet for a vehicle with more than two axles, except a bus; the vehicle length is greater than 45 feet for a bus; or the vehicle length is greater than 100 feet for a vehicle combination, except a vehicle combination listed above.
Operators of oversize vehicles are responsible for checking the clearance of the vehicle and its load through any toll lane or canopy and for checking structures on a way for available clearance.
| General sign requirement | An oversize vehicle that does not require an escort must display an OVERSIZE LOAD sign. | |||
| Escort sign requirement | When an escort is required, the escort must have an oversize load sign. | |||
| Type | Size | Lettering | Background | |
| General signs | OVERSIZE LOAD | 7'x18" | 10" black lettering with 1.41" brushstroke | Yellow |
| Escort signs | OVERSIZE LOAD | NS | NS | NS |
| General light requirements | NS | |||
| Escort light requirements | Warning lights required | |||
| Type | Placement | |||
| General light type and placement | NS | NS | ||
| Escort light type and placement | (2) flashing amber lights | Visible from front and rear | ||
| Type | Size | Placement | ||
| General Flags | Red material | 18" square | Mounted on all corners or extremities of the overwidth or overlength movement. | |
| Escort Flags | Red material | 24" square | Mounted on right and left side of OVERSIZE LOAD sign. | |
| Size | Placement | Content | |
| NS | NS | NS | |
Escort cars are required as follows:
| Oversize Condition | Number and Placement of Escorts |
|---|---|
| Length of 80 feet up to 94 feet 11 inches | 1 rear |
| Length over 94 feet 11 inches | 2 front and rear |
| Length of 134 feet or more | Massachusetts State Police and 2 front and rear |
| Width of 12 feet 1 inch and up; dozer with blade attached | 2 front and rear |
| Width 12 feet 1 inch to 13 feet 6 inches | 1 rear |
| Width over 13 feet 6 inches | 2 front and rear |
| Width over 14 feet 11 inches | Massachusetts State Police and 2 front and rear |
| Height over 13 feet 8 inches | 1 front |
| Height over 13 feet 11 inches | 2 front and rear |
| Height over 14 feet 11 inches | Massachusetts State Police and 2 front and rear |
| Width over 12 feet operating on Cape Cod | Massachusetts State Police and 1 escort |
Escort vehicles must be light truck or passenger vehicles equipped with two flashing amber lights visible from the front and rear. Red flags, 24 inches square, must be mounted on the right and left side of an OVERSIZE LOAD sign on the vehicle.
| Daytime | Vehicles that are over 12’ wide, 80’ long, or 13’ 11” in height may travel only during daylight hours with additional time of day limits. | |||
| Weekend | Travel on weekends is allowed Saturdays and Sundays until noon. | |||
| Holidays | Special permits are not valid from noon the previous day until noon the day following holidays: • New Year’s Day • Memorial Day • Independence Day • Labor Day • Thanksgiving Day • Christmas Day | |||
| Visibility | No movement can be made under permit when there are large areas of hard packed snow or ice on the surface of the road or during a snowstorm. | |||