On some roads, you'll notice that the route passes between impressive rock faces. It's a telltale sign that a hill has been blasted open so drivers don't have to tackle the steep slope.

However, this approach isn't feasible for every hill out there. More often than not, a road will be constructed directly on the slope, with signs warning drivers—especially truckers—about the grade.

Failing to account for the hazards of a steep road can be devastating. This became clear in Connecticut when a dump truck's brakes failed on a 10 percent grade in Avon, causing the truck to plow through 20 vehicles stopped at a traffic light at the bottom of the hill. Four people were killed in this incident, and 19 others were injured.

Relying too much on your brakes during a descent can be especially dangerous. Harry Gorge, author of the 2011 book "Common Sense Guide to Driving a Truck," says excessive braking will cause the brakes to overheat. This increases the possibility that the brakes will be less effective or fail entirely.

Engine braking is a more effective way to reduce your speed while traveling downhill. MAT Foundry Group, a British manufacturer of automotive safety parts, says that when you take your foot off the accelerator, the airflow to the engine is restricted. This forces the cylinders to work against a higher manifold vacuum, reducing the engine power and causing the vehicle to decelerate.

This effect is apparent even on level roads, allowing you to slow down without using your brakes. As a result of engine braking and friction, taking your foot off the accelerator allows you to reduce your speed when you are approaching a red light, stuck in congestion, or otherwise in a situation where you need to slow down.

Engine braking has the added effect of limiting fuel consumption, allowing you to burn less gas during a downhill coast where it is not really necessary. The engine is also built to withstand engine braking, so you won't put any unnecessary wear and tear on it.

Of course, the momentum of the descent can cause your vehicle to pick up speed even when your foot is off the gas. For roads with long, steep descents, you should shift to a lower gear. This has the effect of increasing the engine braking, further limiting the vehicle's power.

Don't wait until you're on the hill to make this shift. Gorge recommends downshifting just before a steep grade starts so you'll be traveling at a safe speed when you start the descent.

While a lower gear will help you reduce your reliance on the vehicle's brakes, it won't eliminate it entirely. You can still overheat your brakes if you use them too frequently.

It is not advisable to slow down by making a series of short brake applications. It takes time for the brake drums to cool down, and frequent braking will cause them to slowly heat up instead. You also don't want to ride your brakes during the descent. Central Automotive, a business in Kent, Wash., says the brake fluid can reach the boiling point if your brakes heat up too much.

When your brakes or brake fluid become too hot, you'll experience brake fade. This means the brake pads are not producing as much friction, and therefore the stopping power of the brakes is reduced.

The best way to brake when going downhill is to press the brake pedal firmly when you feel the vehicle is starting to pick up too much speed. Gorge says this should slow your vehicle down to about five miles per hour below the intended speed. Central Automotive recommends pressing on the brake for about five seconds before releasing it. If you find yourself braking too frequently, shift to a lower gear.

If your brakes are becoming less responsive or you notice an acrid smell indicating that they are overheating, find a safe place to pull over and let your brakes cool down before proceeding. The Mount Washington Auto Road, a popular scenic route up the New Hampshire mountain, provides several turnouts for this purpose.

On some roads, you'll encounter a series of both uphill and downhill slopes. For particularly steep climbs, you'll want to make sure your engine isn't overheating. The city of Colorado Springs recommends turning off your air conditioning and shifting to a lower gear if your engine starts struggling during the climb.