Chapter 12: Towing a Trailer

Towing a trailer safely requires a unique set of skills and knowledge beyond those needed for everyday driving. Understanding the physics of a combined vehicle, the legal equipment requirements, and the proper driving techniques is essential for preventing loss of control, which can lead to devastating crashes. Mastering these rules is crucial for protecting yourself, your cargo, and everyone else on the road.

Towing a light, non-commercial trailer involves connecting a separate, unpowered vehicle to a passenger car or truck. This fundamentally changes the way the vehicle accelerates, brakes, and turns. Wisconsin law mandates specific equipment and procedures to ensure that towing is done safely and that the combined vehicle does not pose a hazard to other road users.

Equipment and Loading

Before towing, a driver must ensure the vehicle and trailer are properly equipped and connected. The right equipment and correct loading are the foundation of a safe trip.

• Hitch: The hitch connecting the trailer to the tow vehicle must be appropriate for the weight of the trailer. It must be securely attached to the vehicle frame and have a locking device to prevent accidental detachment.
• Safety Chains: Every trailer must be coupled to the towing vehicle by two safety chains. These chains must be strong enough to hold the trailer’s gross weight and must be crossed under the trailer tongue in a crisscross pattern. This “X” pattern creates a cradle that will catch the trailer tongue if the hitch fails, preventing it from digging into the pavement and causing a loss of control.
• Lights: The trailer’s lighting system must be connected to the tow vehicle’s system and be fully functional. This includes taillights, brake lights, and turn signals that work in sync with the tow vehicle.
• Brakes: In Wisconsin, a separate braking system on the trailer is legally required if the trailer’s gross weight is 3,000 lbs or more. These brakes are typically activated electronically or by a surge mechanism when the tow vehicle’s brakes are applied.