What Is a Runaway Truck Ramp?

The off-ramps that lead to dead ends on downhill sections of the highway are called runaway truck ramps or escape ramps. For most people in cars, these ramps might just seem like novel sights. However, they can stop an out-of-control truck from wreaking havoc and save lives.

What Is an Escape Ramp?

Escape ramps are the emergency areas located alongside downhill roads that allow vehicles to safely stop if their brakes fail.  Escape ramps are frequently called runaway truck camps because fully loaded trucks frequently use them.

What Are Runaway Truck Ramps For?

Downhill highway sections pose a major challenge for a truck’s braking system because semitrucks can weigh up to 80,000 pounds when fully loaded.

Given their immense weight, trucks can easily build momentum when going downhill. If they pick up too much speed, they’ll have too much inertia and their braking system won’t be able to slow them down. Runaway truck ramps are built to prevent them from turning into battering rams that can crush cars and demolish structures.

How Does a Runaway Truck Ramp Work?

Runaway truck ramps can work differently depending on their method of slowing down trucks. There are several different runaway truck ramp types, including the following:

Gravel or Sand Bed

Escape roads are often lined with loose gravel or sand. When a truck drives over these loose surfaces, the wheels will dig into the sand and create a lot of rolling resistance, slowing down the truck. Gravel or sand beds can contain loose rows of sand that are perpendicular to the direction of travel. These rows of material dissipate the truck’s energy. However, hitting these rows can harm drivers, since it can be a jarring and violent experience.

Mechanical Arrestor Ramp

Some truck ramps use a catch-net system that makes use of a series of cable or stainless steel nets that work like rubber bands. They’re designed to wrap around the front of a truck and slow it down. Arrester ramps can also be installed on downhill slopes.

A truck that uses an arrester ramp will be damaged and the truck will need to be towed. Additionally, arrestor ramps need to be reset after each use.

Gravity Escape Ramps

Ramps can use gravity to slow down a runaway truck. Ramps are also a good way of slowing down trucks without damaging the truck itself and harming the driver. However, uphill ramps need natural inclines for them to be practical. This is why they’re only typically built alongside hills and mountains.

Why Semitrucks Often Use Runaway Truck Ramps

A typical car uses hydraulic brakes to slow down. While this braking system is effective for a 3,000-pound car, hydraulic braking systems can’t handle an 80,000-pound loaded semitruck. Instead, trucks rely on compressors to feed air pressure into tanks, which subsequently distribute pressure to the truck’s air brakes. These brakes can fail when a driver brakes excessively, causing the air tank to lose air faster than the compressor can provide. Without any air pressure, then the truck won’t have braking power.

Additionally, brakes can also fade when they’re overused. This happens when the truck’s drum brakes accumulate too much heat, which causes characteristics of the metal to change and result in less friction. On long downhill descents, trucks are prone to encountering these brake issues.

Luckily, trucks are also fitted with Jake brakes, a feature in truck engines that allows them to have stronger engine braking. Experts say that drivers should set their transmission on a low gear to enable engine braking immediately upon cresting a hill. They shouldn’t wait for the truck to speed up before shifting to low gear, because this could be too late. To prevent overheating, drivers should also exercise braking in quick bursts of around three seconds instead of braking constantly.

If you find yourself barreling down a road before a runaway truck ramp, try to remain calm, keep your wheel straight, and brace yourself. You shouldn’t have any issues if the ramp is designed well.