MONTANA STATE PILOT CAR REGULATIONS

When Permit Is Needed
Over 8’6″ wide, Over 14′ high, Trailer over 53′ long

Times Of Movement
Continuous travel is allowed for loads, not over 10′ wide (9’6″ for baled hay & hay racks)
14’6″high, 75′ long w/ overhang,110′ long w/ no overhang on non-interstate
Non-reducible 10′ or less may travel on interstates
Daylight travel only, 7 days a week, for loads not exceeding 18 wide, 18′ high (over 17’ high must have Helena approval), 120′ long
w/ overhang,110′ w/o overhang on non-interstate
Daylight travel only Mon.-3pm Fri. (no travel from 3 pm Friday until sunrise Mon.) for loads that exceed 18′ wide,120′ long and 18′ high (over 17’ high must have Helena approval) Exceptions: implements of husbandry
Travel prohibited on the following holidays: New Year’s Day, Memorial Day, Independence Day, Labor Day, Thanksgiving, Christmas
(If a holiday falls on a weekend or Friday-no travel on F-Sun; if a holiday falls on Monday-no travel Sat-M; if a holiday falls on T-Th-no travel only on that day)

When Pilot/Escort Vehicle is Required

http://www.mdt.mt.gov/publications/docs/manuals/truckers_handbook.pdf 
A. On interstate:
Over 16’6” wide- 1 rear
Over 120′ long- 1 rear
B. On 2-lane or multi-lane non-interstate:
Over 12’6” to 16’6” wide- 1 front
Vehicle or load exceeds 16’6”’- 2 (front & rear)
Over 110′ long- 1 rear
Over 10′ wide & not equipped with lights & signs- 2 (front & rear)
Over 17′ high (before permit- route survey)
C. Convoys:
No more than 5 OS/OW loads needing escorts may convoy if width not over 14′ (or 15′ w/ projections and not over 120′ long)- 2 (front & rear); not more than 5 may convoy if a length of any unit is over 110′ long on the interstate highway

Dept. of Transportation Permits Office
Hours: 8:00am-5:00pm MST; M-F

Dept. of Transportation
Motor Carrier Service Div
P.O. Box 4639
Helena, MT 59604
406-444-6130 (permits)
Fax: 406-444-7670/0800
http://www.mdt.mt.gov/publications/docs/manuals/truckers_handbook.pdf