Home / Monster Trucks / Keeping A Monster Safe-A Look at How the MTRA Ensures a Safe Event

Keeping A Monster Safe-A Look at How the MTRA Ensures a Safe Event

Despite standing over 10 feet tall, 12 feet wide, and weighing 11,000 pounds, a monster truck and the sport itself puts safety as lead priority.

When one is at the wheel of a piece of machinery that has so much horsepower, and so much weight, immediately one may feel intimidated.  At tires sitting nearly six feet in height, the feeling of uneasiness can set in.

A firesuit, a helmet, and a molded seat may feel secure, but that fear still lingers.

From the outside, looking at a monster truck may seem like one is looking at a vehicle that is simply made for an adult who wants to play with a big toy.  The kid in every one of us, no matter what age, feels some sense of pride when they are looking at a machine that weighs nearly six tons, and costs upwards of $250,000.

What is more known, but maybe not as understood, is exactly why when these men and women get into these beasts, they don’t feel intimidated.

Instead, they feel secure, knowing that despite the size, the power, and the enormous footprint they leave from the tires, these trucks are safe to run.  If they are not safe, they simply will not perform.

Beginning in 1987, the monster truck industry took a major change.  With the advent of side-by-side competition quickly becoming even more popular than the simple car crush, sled pull, or mud run, things needed to be taken into account to make sure everyone was competing in a secure and safe environment.  But, it couldn’t just be about the safety of the drivers.  It meant making sure those on the sides of the tracks, such as crews and officials, were safe, and even those that paid admission fees were treated in a safe manner.

By this time, truck owners, drivers, and promotion companies all got together to ensure that the sport of monster truck racing would grow, but also be safe for many years to come.

Enter the debut of the Monster Truck Racing Association, or as the MTRA as it is known.

It has been 29 years since it’s inception, and the MTRA still has one focus:  keeping the sport safe for all.  The trucks may be a lot different, and the competition has evolved in many aspects, but the singular goal is always making sure the sport is safe for all that are involved.

There are many things that go into making a monster run, but there are a lot more that go into making sure a truck is safe for competition.  Here’s a look at just a few of the big requirements that the MTRA has in their rule book for competition:



Although these trucks have a lot of power, and a lot of torque, one of the more vulnerable areas that has seen failures is both the brake system and the driveline.

The power of the engine and transmission goes through the transfer case and to the two massive driveshafts, which in turn go into the axles.  On occasion, some of these components will fail, and when they do, the pieces can become heavy missiles.

The MTRA knew this, and when it came to the driveline, there was little messing around as to protection for the people in the stands and on the ground.  Each driveshaft is wrapped in a looped cage, and that cage is required to be painted or powdercoated in a “highly visible” color.  Many MTRA-certified trucks elect to go with really bright colors, such as red, lime green, or even silver.  As long as the color is visible, the truck is in compliance.

The cage itself is there in case should a driveshaft fail, become dislodged, or break.  If that happens, the cage will hold the broken part and prevent it from falling to the ground.  It’s contained to a certain area, and thus preventing any parts from possibly shooting out from under the truck.

In addition, all the U-joints that go into the transfer case and into the axle have their own cage or shield, and are there for the exact same reason.

One other aspect that is key in safety for these trucks is the brake system.  Many of these monsters do not run brakes at the wheels, due to the fact the stress on each wheel is too great, there is a high risk of failure.  Instead, about 90 percent will run what are termed “pinion brakes,” where the brake rotor and pads are at the center of the axle.  This puts the brake pressure at a central point, and can slow the truck down much easier.

Just like on a passenger car, brakes can fail, whether it be a rotor, pad or caliper.  So, the MTRA requires a cage or shield around the brakes that will collect any broken parts if they fail.

For the trucks that do run brakes on each wheel, such as the Bigfoot trucks that run the ZF axles, the brakes are covered with a shield both on top and on bottoms so deflect broken pieces towards the ground.

Finally, one of the newest additions to the MTRA safety when it comes to the driveline has to do with the wheels and hubs.  Possibly the weak link on any truck is the planetary hub, because a hard landing can risk the wheel coming dislodged from the truck, and rolling away in any direction.  In the last few years, a tether or restraint system has been required to keep wheels from coming loose and rolling away from the truck.

Last year in Bloomsburg, Pennsylvania, this was tested twice in one weekend.  Dave Radzierez in the XDP Diesel broke a wheel not once, but twice, in one weekend.  His cable tethers prevented the tire from rolling away, and instead allowed him to be towed, on in one instance drag, the broken truck to the pits.  Meanwhile, Mat Dishman had a hard landing in the Rammunition Ram, and broke his front hub.  The Hall Brothers team runs a steel restraint system, which is placed over the hub on all corners.  This kept the tire not just on the truck, but also in a location to where it could safely be driven.

All of these safety aspects are mainly seen on the bottom of the truck, and all are in place because a truck with big power needs to make sure all those little pieces don’t cause major injuries.




The heart of any of these trucks is the power, how it gets to the tires, and how it keeps running.  With engines running easily above the $25,000 price range, these have become expensive to run and maintain.

At the same time, compared to years ago, being able to make sure these beasts keep their parts within the frame rails has always been top priority.

Per the rule book, the engine on the trucks must only have a 10% blower drive coming from the supercharger that is on top of the actual block.  However, in addition to that, should the supercharger backfire, and actually explode, teams are required to use blower straps that are attached from the supercharger down to the frame.  This prevents the supercharger from going up like a rocket.  Plus, the actual blower belt that powers the entire engine is surrounded by a shield or cage.  When those rip apart, it’s like in NASCAR when a tire explodes.  The rubber rips at the metal, and that can tear up a lot of equipment.

Along with the shields on the belt, the chassis themselves are also required to have shields on either side of the engine.

Reason this is important is if something internally breaks and happens to shoot out the side of the block, instead of being a projectile, it hits the shield and falls to the ground, keeping it close to the truck and away from individuals.

The transmission follows the same aspects in that it also is supported to the chassis, although many trucks now because of the lexan sponsor panels that are on the lower part of the chassis will use those as shields in case any parts come out the transmission.

The final piece of this entire system is fuel.  Monster trucks used to run on gasoline, a high-octane content.  However, because of the huge threat of fire, especially when ignited at extreme temperatures, teams started running methanol, which will still burn but also will do so at lower temperatures.  It also will burn clear, which often is hard to see when there is a fuel fire in one of these trucks.  Gasoline can still be used to start the trucks, but if today’s machines tried to run an entire race, much less freestyle, using gasoline the engine will misfire and eventually shut down because of the fuel in the system.

All fuel lines, and oil lines, are braided because of strength and durability.

But, the key component in the system is the actual fuel cell.  Inside the cell is a fuel bladder, preventing any fuel from accidentally escaping and leaking out the aluminum cell and potentially becoming a fire hazard.  The fuel cap is vented to help release the pressure, but even so that is often not enough to prevent damage.  It has happened under certain circumstances where a fuel cell will get damaged.

That happened last summer when Bigfoot #11 took a violent impact in Springfield, Illinois, during a rollover.  The truck hit nose-first, and the impact was enough to twist the chassis.  The fuel cell was broken, with raw fuel falling out.  However, the on-board fire system made sure any ignition wasn’t happening.

All these will make sure a truck runs, but without the driver, it won’t go anywhere.



These trucks, although advanced in technology and power, still need someone to operate them.  Although even the driver itself has changed quite a bit over the years.

During the early days of the sport, owners and drivers would do their performances wearing a helmet and seat belt.  Outside of that, the look of who was at the wheel had similar characteristics to someone that was driving down the highway to the 9-5 job.  T-shirts, blue jeans, sneakers or boots; it was a casual Friday every time one got behind the wheel.

Of course, after a few years of this, and especially when racing became extremely big, everyone had to smarten up in not only the way they looked, but also how they felt inside the truck.

Up until 1989, it was not mandatory for a truck to run with a roll cage around the driver although some sort of roll bar was highly recommended.  But by the late 1980’s, all trucks were getting set up with full roll cages for safety, including cross-bracing to make it stronger should an impact happen at a certain corner.  In those days, the driver was in the same position of every vehicle in America, the left-hand side.  Many teams because of that would have padding should they come in contact with the bar.

A few trucks still have the “conventional” style seating, but many have gone to a center-steer setup, and the roll cage has become more detailed in both the size of tubing, and where the tubing must triangulate together for strength.

The seat as well has come a long way, along with the belts for the drivers that strap in to drive these big machines.

Today’s racing seats are custom made not for a truck, but for the driver.  It is fitted directly to their body, making it impossible for another driver to hop in a truck and run it unless a seat is either swapped out or a lot of padding is added or taken away.  As far as seat belts, that has changed as well.

Years ago, some drivers actually would hang out the window while driving, while being belted in just around the waist.  This turned out to be bad both in trying to drive, and also later in life.  Former Bigfoot driver Jim Kramer has said that those years of hanging out the window, like many others he competed against, has caused a lot of shoulder issues along with other injuries related to his driving style.

Now, hanging out the window isn’t even thought of unless it’s just to greet the fans after a run.

Every truck has a five-point safety harness that goes around the shoulders, waist, and the pelvis.  These belts also have a quick release in case of an accident or emergency, which allows the driver to quickly get out.  These belts also provide the way to keep a driver’s neck from being thrown around, which is something that has gone hand-in-hand with the driver safety gear.

It was put in writing back in 1989, and has upgraded through the years due to improvements in materials, that drivers were required when operating the truck to be in full firesuit.  Whether a simple car crush or an all-out freestyle, the suit is to be full fire-retardant from head to toe, with tennis shoes/sneakers not allowed to be part of the suit.  Although not seen over the driver suit, some drivers will wear a kidney belt to protect their kidney area and also support the lower back.

Drivers also must have a helmet with eye protection.  Although the windshields are not glass but rather lexan, there is always a risk of something puncturing the field of vision for the driver.  So either goggles or a face shield on the helmet is required.  This becomes useful when drivers decide to cut the windshield in performances where it’s muddy, so that they have clear sight but also have their personal vision clear.

Whiplash is also a big issue in these trucks, so normally teams would wear a neck collar to support the neck and the weight of the helmet.  The problem still is that the collar only protects to a limit.

Now, as is seen in NASCAR, many will wear some type of head and neck restraint system.  Recently retired Bigfoot driver Dan Runte was the first to wear a HANS device in a truck, and did so back in 1999 when he set the then-Guinness World Record jump of 202 feet.  Since then, the HANS device has gone from big and bulky to being very lightweight but strong.  It attaches to the helmet and is held down by the shoulder belts, keeping a driver’s head from flying forward on a hard impact.

Safety of the trucks and the driver is absolutely critical when performing, but all of these safety aspects pale in comparison to a piece of equipment that is on the truck, however is at the control of someone that is not even behind the wheel.


The annual MTRA tech meeting in December modified many of the above safety measures, many of which were suggested and discussed with drivers and owners.

With the input, the MTRA decided to require all drivers to run a head-and-neck restraint system, whether it be the HANS device or some other safety measure to prevent the driver’s head from flying forward on a landing or an impact.  Neck collars now for race vehicles are outlawed, mainly due to the fact the new restraint systems out-perform the collars in safety.


MTRA member and Family Events Safety Coordinator, Paul Monroe, watches a truck perform in Bloomsburg, while holding the Remote Ignition Interrupter (R.I.I.) remote.


What is the one thing on a monster truck that is used when needed, but is always running?  It’s not the engine, although electricity is part of the equation.  It’s not fuel, although it’s part of what it helps stop.

It is instead something that changed safety in these trucks forever.

Developed by the MTRA, along with many drivers such as Bigfoot’s Bob Chandler, Jim Kramer, and Goliath’s Alan Tura, the most critical part of any monster truck is the Remote Ignition Interrupter, or R.I.I. for short.  It is on every time a truck is running, but is only used when the situation calls.

This is a safety requirement by every promoter and every truck, and no truck will run without it.

What the R.I.I. does is in case there’s an issue with the truck, mechanical or driver, or in situations where a driver is in a tough situation or is potentially rolling over or if the driver suffers an injury and cannot save himself/herself, it shuts down the electrical system to the truck.  There’s no spark plug firing, no current to the battery, and no fuel going in the engine.  The truck literally goes silent.

There isn’t just one switch for the R.I.I. on the truck; there are three.  One is in the cab with the driver, while the other is a pull-ring on the back of the chassis.  The third, where the name comes from, is actually a remote which years ago was used by a team member during performances, but then were used by track officials.  This gives three opportunities to make sure a truck isn’t running in case of trouble.

Every truck doesn’t just go through an R.I.I. test one time during a performance to ensure it works.  It actually is tested every time the truck is run.  Even a simple car crush at a dealership or tire supplier, the R.I.I. is used and tested because anything can, and has, happened.

How the test works is not complicated.  A driver will fire the truck up to come out, and in the case of racing, could groom the lane to get the best bite.  When they are done, the driver pulls the truck to a stop and holds his/her hands out the window, ensuring no controls are touched.

A track official will then hit the remote to test it out.  If the truck shuts off, then restarts, the driver can race or perform.

Each truck also has two channels to run on, designated by the lights in the cab.  A red light to the right of the cab means “Channel Right,” while a yellow light to the left of the driver means “Channel Left.”  If one channel doesn’t work, officials indicate they are switching to a different channel to test it out again.

No matter the promoter, driver, or truck, if the truck doesn’t shut off when the official uses the remote, that truck will not perform.  It is non-negotiable, it isn’t a deal where “I’ll get it when it happens.”  If the track official cannot shut the truck off with the remote, that truck will not perform until the problem with the R.I.I. is fixed, and then retested.

When the truck is performing, the official is at the control should a driver get in a bad situation, however he or she will not immediately kill the truck if a driver is trying to prevent a roll.  MTRA officials, especially those that run with Family Events, give drivers a chance to save the truck, to an extent.  Often, if a driver rolls and the roof touches the ground, the remote is hit, and immediately officials, safety personnel, and sometimes crew members will rush to the truck.  The first official on the scene, even if the remote is hit and the truck is shut down and even after the driver hits the one in the cab, is to pull the R.I.I. ring on the back of the truck.  This guarantees the engine will not run and potentially cause more harm.

No matter how many safety aspects come with a truck, front to back and top to bottom, the R.I.I. system is by far the most important safety component for this sport.  Without it, all trucks are safe.  Without it, no truck will perform.


For over 40 years these trucks have given crowds a thrill, and have done so with very few major incidents at shows.  From stock trucks that were built up bigger, to today’s several thousand-dollar racing machines, the industry has changed drastically.  But, so has safety.  It has and will continue to be top priority in the sport, and will always improve in ways to make it better for those that are wanting to see the future of monster trucks.

To look more in-depth into the safety requirements of the Monster Truck Racing Association, visit MTRA.us and download the full rule book.

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