What Is Hill-Descent Control? How Does It Work?

Imagine yourself perched atop a steep, snowy hill. If you’re rocking snow pants and a parka, and there’s a sled beneath your snow-insulated cheeks, you want to slide down that slope with as much speed and as little friction as possible. It’ll be fun!

As fun as that might be, if you find yourself atop a hill in an SUV packed with three rows of beloved family members, you’ll likely have a different goal in mind. A slow, safe, controlled descent is what we’re after, which can be rather tricky and unnerving to accomplish with brake-pedal modulation alone. Hence, hill-descent control.

Land Rover introduced hill-descent control on the compact first-gen Freelander, which reached American dealers in late 2002. The Freelander didn’t have the low-range gears that aided low-speed descent in more conventional Land Rovers (and Jeeps, Land Cruisers, etc. ).

That system and all those that have followed operate in the same basic manner. Once the driver has activated hill-descent control and chosen a maximum speed, the vehicle draws on its traction-control and anti-lock braking systems to minimize tire slip and ease you down the slope. The driver need not touch the gas or brake pedals, and can therefore concentrate on steering around potential hazards that lay ahead. The ABS pulses cause the tires to skid slightly over a given terrain, often building up little piles of dirt, scree, or similar materials in front of the wheels; these small “obstacles” can provide further assistance in, uh, controlling a hill descent.

Unlike cruise control, hill-descent control only operates at a low range of speeds and offers finer adjustments. Some systems limit usage to under 5 mph and offer minute speed adjustments to the tenth. Hill-descent control is marketed using that exact phrase across most automakers, though there are some exceptions. More than 20 years after its development, it has become a staple of the modern SUV.

These vehicles offer hill-descent control as standard or optional equipment.