Chapter 12: Towing a Trailer

Safely towing a trailer requires a distinct set of skills and knowledge beyond those used for everyday driving. The added weight and length dramatically change a vehicle’s handling, acceleration, and braking capabilities. Understanding the specific equipment laws, proper loading techniques, and necessary driving adjustments is crucial for preventing loss of control, serious collisions, and for passing the driver’s test, which may include questions on these responsibilities.

Equipment and Loading

Before towing, a driver must ensure the vehicle and trailer are properly equipped and the load is balanced and secure. Failure to do so can lead to equipment failure, dangerous trailer sway, or loss of the entire load.

Required Equipment

• Hitch: The hitch must be appropriate for the weight of the trailer and securely attached to the tow vehicle’s frame. It is critical that the hitch ball size matches the trailer’s coupler size.
• Safety Chains: Every trailer must be connected to the tow vehicle with two strong safety chains or cables. These chains must be crossed under the trailer tongue (in an “X” pattern) and attached to the tow vehicle. They should have enough slack to permit sharp turns but be short enough to prevent the trailer tongue from dropping to the ground if the hitch fails.
• Lights: The trailer must have a functioning light system that connects to the tow vehicle. This includes taillights, brake lights, and turn signals that work in sync with the tow vehicle’s lights. The trailer’s license plate must also be illuminated at night.
• Trailer Brakes: In Alabama, a separate braking system is legally required on any trailer with a gross weight of 3,000 pounds or more. These brakes are typically activated by an electronic controller in the tow vehicle and are essential for safe stopping with a heavy load.

Proper Loading

An improperly loaded trailer is the primary cause of dangerous trailer sway. The key is to manage weight distribution correctly.

• The 60/40 Rule: This is the most important principle of loading. Approximately 60% of the total cargo weight should be placed in the front half of the trailer (ahead of the trailer’s axle), and 40% should be in the rear half.
• Tongue Weight: Proper loading results in a “tongue weight” (the downward pressure on the hitch ball) that is 10-15% of the total trailer weight. Too little tongue weight will cause the trailer to sway, while too much will weigh down the rear of the tow vehicle, lifting the front wheels and reducing steering control.
• Secure the Load: All cargo must be tied down and secured to prevent it from shifting during travel or falling off the trailer, which could create a severe hazard for other drivers.
• Load Extension: If a load extends four feet or more beyond the rear of the trailer, it must be marked. During the day, a red flag at least 12 inches square must be attached to the end of the load. At night, it must be marked with a red light visible from at least 200 feet.