How to Avoid Getting Killed in Your Big Rig...

Drivers: Did you know......(?)

1. Trucking is a very dangerous profession, about 600 drivers a year die in highway accidents.

2. Driving certain types of rigs like tankers and flatbeds is probably the most dangerous major occupations in the country.

3. About 55% of all class 8 (semis) driver fatalities occur in rollover accidents.

4. Another 10% occur in fuel oil fires.

( For the latest UMTRI statistics from TIFA -trucks involved in fatal accidents- studies, click below.)

UMTRI 1. ..... UMTRI 2. .... UMTRI 3.

If you avoid these two types of fatal accidents, you can reduce the chances of getting killed on the job by almost 2/3!  Here's how:


- Diesel fuel is hard to ignite, but when you've got 100 gallons or so on board it can make a real mess out of the driver and the rig if it catches fire following an accident. Research suggests that a large energy source is required to ignite even warm diesel oil ( the fuel in the tanks is heated by recirculation through the pump).

- You probably can't ignite a large diesel leak -like from a ruptured tank- with sparks or by hot surface ignition (like an exhaust manifold). The most likely ignition source for a fire following a rollover or collision is the battery box. If you short out or crush the batteries following a tank rupture you may get a large fire. If you can't get out of the rig you had better hope the rollover or collision killed you, it'll get real ugly in that cab if you've got a large diesel fire under it.

- So: MOVE the BATTERIES! Put them behind the cab in front of the fifth wheel, or inside the frame rails so that the frame rails protect them- if there is room there. Get a good electrical mechanic to do this for you in either case, and make sure he checks for interference if you decide to put them inside the frame rails. If you can't move the batteries, put a cage around the box, make it out of heavy gage angle iron or steel tubing. Don't weld the cage to the frame rail! This will ruin the heat treatment and the rail will break. Bolt it on. The idea is to prevent the batteries from being crushed and/or shorted out in an accident.

More on Fires:

Go to:




Downhill braking


But First:

We are researching truck accidents, if you or someone you know of has had a rollover or fuel fire accident we would like to talk to you. CALL: TECHNICAL SERVICES: 360-576-8880, e-mail, or write: P.O.Box 2806, Vancouver, WA 98668. We would like photos, police reports, information about injuries, tractor and trailer info., etc., but contact us with whatever information you have. We can also assist with technical support for investigation or litigation for any accident or crashworthiness case.. Don't hesitate to call or write regardless.

to the TECHNICAL SERVICES homepage



1. The Problem:

- Big rigs roll easily. You can put a number on the tendency that a vehicle has to rollover- the higher the better (safer). Full size cars are about 1.3, pickups are 1.1, Jeep type vehicles are 0.8- 1.0. Fully loaded semis are about 0.4 or lower. A half empty tanker with a bad suspension might be 0.15! These numbers are the cornering "g's" required to roll the vehicle. No car can generate 1.3 g's in cornering but your rig can probably generate 0.4 g's going around a corner or in a variety of other maneuvers involving steering. If you go around a curve too fast, you will go over, but you probably already knew this. Here are some things you may not know:

- You can go over in a curve without going to fast for the curve if your rear tires strike something (like a curb) while you're cornering. Articulating vehicles (5th wheel type) with rubber tires outrack when turning above a certain minimum speed, typically 15 mph. This is inherent to the vehicle and not the result of poor driving. Your trailer axle might be 2 feet outside your steering axle if you're pulling a long trailer. Picture this: You're coming down a freeway ramp, turning right ( a right hand curve). Your left front tire might be 1' inside the fog line while your outer left rear tire might be 1' outside the fog line. What's out there to trip you and turn you over?

- You can probably roll your rig at speeds as low as 5 mph, especially on slopes or where a strong tripping influence is present. You can roll backing up if you're jackknifed.

- Many rollovers happen when drivers try to return to the road after putting a tire off the pavement. You can rut in soft ground or catch a pavement separation here and go over. If you put a wheel off the pavement or even onto a paved shoulder that may have separations, straighten the rig out and bring it to a stop. Don't try to return to the road at speed. Get out of the rig, carefully inspect the site and determine that you can get back on the road without catching or tripping a tire before you move out again. If you do decide to drive it back on, return to the road as slowly as possible and at as shallow an angle as possible. The more steer you put in the easier it is to go over. If it looks too bad, call a wrecker! We are not kidding here, we know that thousands of drivers have gone off the road and come back without rolling the rig, but hundreds of others have also tried and died in the attempt. How big a risk do you want to run for $ 0.25/mile ?

- Treat any load that can move on you like a load of dynamite and drive accordingly.

- DEATH by sloshing: Shippers who insist on running tankers less than 3/4 full are putting you under unnecessary risk.

- Lane changes and similar road maneuvers can roll you, this goes double for double drivers and triple for triple drivers.

Can You Survive a Rollover ?

- Until very recently, there were probably no cabs sold in this country that would not go flat if you put them on their roofs. Stronger cabs are available in Europe, they meet the EEC or Swedish standards, but this doesn't do you any good unless you are reading this in Stockholm. Truck manufacturers have paid plenty to the widows and orphans of dead drivers because of these unsafe cabs.

- Sometimes the trailer or the load will prevent the roof from contacting the ground when you do a 180 degree roll (1/2 turn), you're better off here, but no guarantees. Without a high trailer or load, if you roll 180 degrees or more and put the tractor on its roof it will collapse down to the engine line. Headache racks and cargo barriers will not save you, they're too low and too weak. If you stay in the cab and remain upright you will probably get killed.

- Some drivers have saved themselves by jumping out of the rig before it goes over. This might work for an opposite side roll but it is hard to recommend this technique. If you roll left (same side roll) and you jump or fall out, the rig may rollover on top of you. A number of drivers are killed each year in 90 degree rollovers when they fall out of the cab and the rig rolls over on them. Evidently the door opens and they fall out because they're not belted up. ( Make sure both doors are locked when you're moving.) If you jump out the high side you are in danger of hitting your head on the pavement or suffering some other injury from the fall. This is still probably better than staying upright in the cab IF the rig does a 180 or better. The problem is that you don't know how far its going to roll. A high van will generally prevent you from going all the way over if the van itself survives the ground contact. Flat beds and tankers roll easier and roll farther once the wheels come off the ground.

- If the vehicle is not going over onto its top then you are better off belted up in the cab, but move away from the strike surfaces and watch out for the doors. If it is going over onto its top, GET DOWN IN the CAB. If you get below the hood line you will probably avoid getting killed. This works in conventionals where there's some room. COE drivers should buy lots of life insurance and try as best they can to get down out of the way of the collapsing roof.

- The problem here is the seat belt. You are better off with the belt on in any kind of accident except for a rollover greater than 90 degrees. In this situation the belt may impede your efforts to get down out of the way of the collapsing roof. You may be able to slip out of the shoulder harness or disconnect the belt however. Learn where that buckle is, practice reaching for it with your right hand so you can release it quickly while pulling yourself down with your left hand once you decide to get out of the way. Big rigs don't roll that quickly, you will have some time to act if you are prepared and know what to do.

- When do you start thinking about saving your life and not the rig? By the time the drive axles start to lift, it's too late to make corrections, assume you are going over. Some drivers think they can save a rig when the trailer wheels come off the ground. Maybe you can but there are no guarantees. Remember: STRAIGHT and LEVEL is what you want, its steering and slopes (combined with weight shifts) that pull you over. If you can't straighten it out and level it out quickly, assume you're going over and act accordingly.

Good News from Freightliner!   (Don't forget to come back!)

Return to the top of page.