Farm Tractors and Implements on the Road….
Size, Weight, and Markings

Mike Rankin
Crops and Soils Agent
University of Wisconsin - Extension

Length  

·         Length limit for a single vehicle is 40 feet; for a combination of vehicles the limit is 65 feet. 

·         There is no length limitation for implements of husbandry when they are temporarily operated upon a highway.  An implement of husbandry is defined as a piece of machinery or equipment designed for agricultural purposes, used exclusively in the conduct of agricultural operations, and generally used off the highway.  

·         Two trailers (wagons) used primarily as implements of husbandry, or one such trailer and any other implement of husbandry, may be pulled by a farm tractor if the overall length does not exceed 60 feet and if the operation is strictly a farming operation.

·         Under no circumstances are more than two implements of husbandry allowed to be pulled by any vehicle at one time upon a highway.  

Height  

·         There are no limitations on height for implements of husbandry temporarily operated on a highway.  The maximum height allowed on all other vehicles is 13 feet 6 inches.  

Width and Weight  

·         There is no width limitation on implements of husbandry temporarily operated upon a highway.  

·         A farm tractor is allowed 9 feet in width when operated on the Interstate highway system, and 12 feet on all other roads.  

·         Loads of hay in bales may be 12 feet wide but the total outside width of the load must not exceed a single traffic lane.  

·         Farmers are not exempt from weight laws.  Weight limits depend on factors such as the number of axles, axle spacing, class of highway, and type of product carried.  

Lighting and Markings  

·         Farm tractors and self-propelled farm implements operated or parked on a public road must have the same lighted headlamps and tail lamps as are required of other motor vehicles.  This means that two headlamps and at least one red tail lamp are required.  If a vehicle was originally sold with two tail lamps, both must be working.  Tail lamps are to be mounted 20 to 72 inches off the ground. 

·         Implements of husbandry, such as farm wagons or other non-self-propelled farm implements, must have either two red tail lamps or two red reflectors on the rear.  Implements manufactured before 1984 are allowed to have only one tail lamp or two red reflectors.  This is in addition to the SMV emblem. 

·         A machine should never be parked on he road with a white work light showing to the rear. 

·         Although amber flashers are not required by law, they are highly recommended and are authorized by law for any situation that requires caution by approaching motorists.  Just like amber flashers, turn signals are not required on farm tractors or self-propelled farm implements by law, but are highly recommended.  

·         During darkness, a red light or red reflector must be located on each side of every vehicle in a train.  

·         During the day, two red flags, at least 12 inches square must be displayed on the rear-most vehicle of a train, one at each rear corner.  

·         SMV emblems requirements apply day and night, in addition to any other lighting or marking requirements.  All SMV emblems must be bright and clean, and should be replaced if faded.  It must be mounted pointing upward, with the lower edge being two to six feet off the ground, and either centered or as near to the left of center of the equipment as practical.

Truck Identification Markings 

For a truck without a trailer, the GVWR (Gross Vehicle Weight Rating) as established by the truck manufacturer is used to determine marking requirements.   If the GVWR of the truck is 12,001 pounds or more, the truck must have the required markings on both sides. 

For a truck (including pick-up) with a trailer, the actual total weight of the combination at that particular time, including driver, fuel, load, etc., is used to determine the requirement.   Any truck-trailer combination with actual weight of 12,001 pounds or more must have the markings. 

Required markings:  At a minimum, must include the owner as listed on the truck registration certificate, and the city and state where the truck is headquartered.  Additional information is allowable. These markings must appear on both sides of the truck.  Letters must be at least two inches tall with at least 1/4" wide brush strokes or lines.  The empty weight of the truck must either be marked on the left side of the truck, or alternatively, written on the registration certificate.