The rise and rise of the soft-roader has led to some head-scratching challenges for automotive engineers.
Like, how to get a vehicle that wants to be a 4x4 down a steep, gnarly hill when it doesn’t have low range gearing to help?
The solution is Hill Descent Control (HDC), which effectively uses the vehicle’s cruise control system to retard downward progress, rather than simply leave it to the driver to wear out the brakes.
The system is usually activated by pressing a button, while the speed of descent is often controlled by clicking the up and down tabs for the cruise control function.
Maximum speed, unlike cruise control, is usually only a few km/h and is achieved by a combination of brake pulsing and gear selection.
It really is a feet-off-the-pedals function, but doesn’t interfere with steering and you can over-ride it by pressing the brake pedal or throttle. Some HDC systems also work in reverse gear.
The first time you use it, HDC can be a bit unnerving as you hear the brakes grab and release, but it’s all normal stuff.
Originally developed by Land Rover and supplier Bosch for the original Freelander in the 1990s using the anti-lock (ABS) braking system as its base, HDC is now commonly used by serious 4x4s as well as the, er, less serious ones.
While we have focussed on off-road use here, HDC can also be a useful on-road in specific circumstances, such as getting down a super-steep driveway.
And while HDC is a big help, it can’t compensate for idiocy. You can still cock up a 4x4 downhill even with it engaged. Your judgement as a driver is still key.