What is an escape ramp

How truck escape ramps are used on steep roads to stop runaway vehicles

Following is a transcription of the video.

Video: Oh! He took it! He took it, dude! Gravel is flying! Dirt is flying!

Narrator: If you’ve driven any one of the many highways crisscrossing the world, chances are you’ve seen one of these: a truck escape ramp.

Some escape ramps slope upwards. Others are flat. Some contain sand, others gravel. But regardless of design, they all serve one purpose: to bring vehicles with malfunctioning brakes to a safe stop. Just how do they work?

When designing a new ramp, state authorities consider factors specific to the road, like how steep the grade is and what road conditions look like at the bottom of a hill. Though they may look different depending on where you see them, escape ramps around the world do have some things in common.

Most escape ramps make use of arrester beds, pools of sand or gravel. The material in the bed is selected for their low coefficients of interparticle friction, meaning when a wheel or axle touches the bed, the material in it moves away from each other, allowing the truck to sink into the gaps.

Like a swimming pool, escape ramps are shallow at entry, anywhere from 3 inches deep, and get deeper, to around 48 inches at 100 to 200 feet in. When a truck enters the bed, it meets little resistance at first, then more as it travels. This means the truck decelerates gradually, reducing the risk of injury to the driver, and stands less risk of flipping over, or capsizing.

When observing escape ramps around the world, three designs stand out: the sandpile bed, the gravity escape ramp, and the mechanical arrester ramp.

This is a sandpile bed. This type of escape ramp contains loose rows of sand perpendicular to the direction of traffic. As a truck collides with the pile, the energy of the truck is transferred to the sand. As the sand is sent flying away at high speeds, an equal and opposite force acts against the truck, reducing its velocity. Impacting sandpiles, though, is. jarring, putting the driver at higher risk of injury, which brings us to the gravity escape ramp, distinguishable by its gradually ascending slope.

In addition to the friction of material in the bed, gravity works on the truck, pushing it down and back. The sloped gravity ramp is more effective than a flat arrester bed.

A 10% grade could allow a truck to halt anywhere up to 85 feet sooner. Gravity ramps are the most cost-effective where natural rises occur adjacent to the road. Some terrains, though, simply do not allow for a naturally occurring gravity escape ramp. So, state agencies have turned to a more experimental form of escape ramp.

The mechanical arrester ramp can be installed on flat ground or even downward slopes. Unlike other designs, this ramp does not have an arrester bed. Instead, it contains a series of stainless-steel catch nets. The nets absorb the energy from a truck collision. Like a rubber band being pulled taut, the force exerted on the truck increases exponentially the further the truck travels. The mechanical arrester ramp then can stop a truck more quickly than gravel or sand arrester beds.

Entering a truck escape ramp is a one-way trip. If the ramp works properly, a truck will either end up submerged or damaged, needing a tow to recover. Despite the expense, agencies urge truck drivers and other motorists to use the escape ramps.

EDITOR’S NOTE: This video was originally published in August 2019.

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Runaway Truck Ramp

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It takes experienced skill to control a fully loaded class 8 truck under any condition. Tweak just one factor, such as driving down a steep grade, and the potential for trouble increases. Even a well-maintained rig that’s regularly inspected and is safety compliant can experience brake failure under certain conditions. When that happens, a runaway truck ramp is pretty much the only safe way to stop a 40-ton missile from taking out everyone and everything in its path.

The Need for Escape Ramps

It’s estimated that sometime in the 1960s highway officials started looking for ways to minimize runaway truck accidents. There’s not a lot of data from before 1980. However, an NHTSA report notes that there were 2450 incidents involving runaway trucks in 1981. Those numbers reveal that heavy-duty trucks speed out of control more often than most people might realize.

The issue is that because of the non-synchronized transmission, downshifting isn’t an option for controlling a semi’s speed when driving down a steep grade. The brakes are the only way to slow the truck down in that situation. But, with a full load, that puts a lot of pressure on the brake system—about 80,000 pounds of it actually. Picking up speed on a downhill grade makes the problem of brake fade worse. Some drivers experience full-on brake failure and before they know it, the situation is out of control.

Different Types of Runaway Truck Ramps

So, how do you stop a runaway rig? Since gravity is typically the cause, it makes sense to use it in reverse when semi brakes fail. Steep gravel ramps running off and up at the side of the road near the end of a steep decline are known as a “gravity escape ramps.” It’s the type of runaway truck ramp most commonly used in mountainous areas. The gravel and the steep rise work together to stop the truck quickly.

Other runaway truck ramp types include:

Sand pile ramps—used on less steep grades, a series of sand piles placed on a short ramp help stop speeding trucks

Arrester bed ramps—a short ramp covered with gravel used on minimal grade slopes

Mechanical-arrester ramps—stainless-steel nets stretched across the road near the beginning of the ramp. This design is similar to the concept used on aircraft carriers to help stop planes coming in for a landing.

Not all ramps go uphill. Some run on nearly level ground alongside the road. Others run into the median. What’s more, runaway truck ramps often have concrete barriers running along the sides. They help keep out-of-control trucks on the ramp and offer additional assistance for stopping and keeping the truck upright. As you can imagine, having to use a runaway truck ramp can cause some damage. Plus, there’s no way other than a tow to get a truck back off the ramp, even if the rig doesn’t tip over after it’s stopped.

Runaway Truck Ramp Placement

There are almost 200 runaway truck ramps in the U.S. Not surprisingly, most of them are in the mountainous western states. When considering where to install a runaway truck ramp, states look at:

• the number of accidents caused by runaway trucks and where they occur
• issues at the end of the grade (is there an abrupt bend? a traffic entry point? any buildings?)
• amount of traffic on the grade and what percentage is heavy-duty trucks

A runaway truck ramp is a good safety measure to have around when you need it. However, using an escape ramp is costly. There’s a fine for utilizing them. Add that to the damage it can cause, then factor in the danger an out-of-control truck poses. Those are the biggest reasons drivers are typically extra-careful when driving down steep grades. It’s also why maintenance is so important.

Properly maintaining heavy-duty trucks keeps them safe. It reduces the number of things that can go wrong on steep grades or straightaways. Fullbay helps fleets improve safety by simplifying PM schedules and keeping track of all repairs and maintenance on every truck in your fleet. The software is easy to implement and user-friendly, so it’s just as easy to operate. Interested in giving it a try? Just fill in the form below:

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Proposed features/escape lane

The Feature Page for the approved proposal escape lane is located at Tag:highway=escape.

Escape Lane
Status:	Approved (active)
Proposed by:	Schumi4ever
Tagging:	highway = escape
Applies to:	,
Definition:	Emergency lane beside long descending slopes for trucks to stop after brake failure
Rendered as:	Red-white checkered area
Drafted on:	2009-05-26
RFC start:	2012-10-12
Vote start:	2012-11-03
Vote end:	2012-11-23

Содержание

Proposal

A runaway truck ramp, runaway truck lane, emergency escape ramp or truck arrester bed is a traffic device that enables vehicles that are having braking problems to safely stop. It is typically a long, sand or gravel-filled lane adjacent to a road with a steep grade, and is designed to accommodate large trucks. The deep gravel allows the truck’s momentum to be dissipated in a controlled and relatively harmless way, allowing the operator to stop it safely.

Rationale

If you are not a driver, you may ask why this is here. But in case you have ever driven any vehicle you know the most important thing there is the brakes. Imagine you are driving downhill and your brakes fade because of excessive use, the only way to stop is using these safety measures. In case any in-car navigation system uses this cartography, the voice can tell the driver «Escape lane 500 metres ahead», something that, as far as I know, no GPS system has any idea of.

Examples

Most motorways have them in case of steep and/or long downhill sections.

Type overview

• Arrester bed: a gravel-filled ramp adjacent to the road that uses rolling resistance to stop the vehicle. The required length of the bed depends on the mass and speed of the vehicle, the grade of the arrester bed, and the rolling resistance provided by the gravel.
• Gravity escape ramp: a long upwardly-inclined path parallel to the road. A large length is required. Control can be difficult for the driver: problems include rollback after the vehicle stops.
• Sand pile escape ramp: a short length of loosely piled sand. Problems include large deceleration; sand being affected by weather conditions (moisture and freezing), and; vehicles vaulting and/or overturning after contacting the sand pile.
• Mechanical-arrestor escape ramp: a proprietary system of stainless-steel nets transversely spanning a paved ramp that engage and retard a runaway vehicle. Ramps of this type are typically shorter than gravity ramps and can have a downhill grade. One such ramp in Avon, CT, USA has an electrically-heated pavement surface to prevent snow and ice accumulation.
• Alternatives: such as a vehicle arresting barrier.

Tagging

I guess highway = escape is the most suitable. Why? These ways/areas are always related to roads, are always a part of them, are always by their side, are always a complement for them. highway = runaway and highway = escape_lane were also considered, but the first is not too clear and the second one may be too long.

Before the escape itself, add access:lanes = * with yes|yes|escape in the case of 3 lanes, of which the right lane leads to the escape.

Given the fact that, according to Wikipedia, there are several escape lane types, an additional escape:type = * would do enough.

Applies to

Ways and areas.

Rendering

Maybe a red-white checkered way/area is the most appropiate, as a lot of them start with this scheme painted on the road. Furthermore, this color scheme creates a high contrast with any other way now rendered in OSM.

This scheme was also considered, but the colors are too flamboyant.

Comments

Please use the discussion page for comments.

Voting (version 2)

The voting was closed on 23 November 2012.

• I approve this proposal. after the update=version 2 The key escape:type =* is fine, but I wished that its possible values would have been listed in this proposal, not only an overview of existing types. As was already mentioned a few times, highway = service would not have been a good choice. —Imagic 14:46, 5 November 2012 (UTC)

• I approve this proposal. sletuffe 14:45, 5 November 2012 (UTC)

• I approve this proposal. —Schumi4ever 15:00, 5 November 2012 (UTC)

• I approve this proposal. —polderrunner 15:38, 5 November 2012 (UTC)

• I approve this proposal. And good point from user Imagic about the escape:type =* values. —Al3xius 20:21, 5 November 2012 (UTC)

• I approve this proposal. —Tordanik 20:42, 5 November 2012 (UTC)

• I approve this proposal. —Fabi2 19:47, 6 November 2012 (UTC)

• I approve this proposal. —Konfrare Albert 22:22, 6 November 2012 (UTC)

• I approve this proposal. —Viking81 21:57, 6 November 2012 (UTC)

• I approve this proposal. —Bielebog 1:05, 17 November 2012

• I oppose this proposal. — A escape line cannot be a separate highway, only a additonal feature.—R-michael 17:31, 18 November 2012 (UTC)

Do you mean even keeping in mind there is almost always some physical separation?

• I approve this proposal. —Qurm 09:15, 20 November 2012 (UTC) (R-Michael can you expand your viewpoint in the Discussion?)

• I approve this proposal. erkinalp 19:51, 21 November 2012 (UTC)

• I approve this proposal. — I ask around Excuse me, I had mistaken there something.—R-michael 08:57, 23 November 2012 (UTC)

• I approve this proposal. —Brogo 13:45, 23 November 2012 (UTC)

The proposal has been approved. 13 votes approved the proposal, 0 votes opposed the proposal (Although one vote was originally for opposing and later changed).

Old votes for version 1 of this proposal

Only change with version 2 : it used to propose the use of the type =* tag. Maybe 2 of those no vote could be copied over since they don’t mention the fact that using type =* was a problem

• I approve this proposal. —Schumi4ever 14:54, 3 November 2012 (UTC)
• I approve this proposal. —PanierAvide 15:12, 3 November 2012 (UTC)
• I oppose this proposal. The main tag is fine, but type =* is not a good subkey because it overlaps with the existing use of that key for relations. Should be replaced with escape(_lane)=* or escape(_lane):type=*. —Tordanik 15:24, 3 November 2012 (UTC)
• I oppose this proposal. Agree with Tordanik, type =* should be replaced with something else. —polderrunner 15:32, 3 November 2012 (UTC)
• I oppose this proposal. as suggested on mailing list and discussion page, I prefere highway = service + service = escape_lane —Pieren 16:21, 3 November 2012 (UTC)

Sorry, but is there any reason for your preference? I can’t see the point in tagging this as service=* —Schumi4ever 16:24, 3 November 2012 (UTC)

• I oppose this proposal. See Tordanik’s comment. I think everything is fine but the proposed use of type =* conflicts with that «almost reserved» tag for relation. I also would vote no to using highway = service for an escape line, it is too far from what a highway = service is. My vote become yes if you change type to anything else. sletuffe 18:38, 3 November 2012 (UTC)
• I oppose this proposal. By removing and eventually replacing type =* with something else my vote will change — Al3xius 11:18, 4 November 2012 (UTC)
• I oppose this proposal. I also prefer highway = service + service = escape_lane and maybe access = no —Janko 12:38, 5 November 2012 (UTC)

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