The burnt-out remains of Aguilera-Mederos' truck. 
 -  Screen capture from

The burnt-out remains of Aguilera-Mederos' truck.

Screen capture from

Hundreds of trucks successfully negotiate the treacherous 50 miles between the Eisenhower Tunnel on Interstate 70 and the city of Lakewood, Colorado, where last Thursday, a driver who wasn't so lucky made international headlines, roaring down the grade, out of control, slamming into stopped traffic in a fiery crash that claimed four innocent lives.

Each day, thousands of truck drivers in places like western Pennsylvania and California and Montana and West Virginia manage to get their trucks down similarly dangerous mountain grades. What went so horribly wrong in Lakewood?

While I'm in no position to armchair-quarterback this one, based on the media coverage (and there's been plenty, including some hair-raising videos), it looks like a pretty clear case of inexperience, coupled perhaps with some maintenance issues, and possibly even some problems reading and understanding the signage on the highway.

A video has surfaced showing what is believed to be the truck in question driving past a runaway truck ramp just a few miles before the accident scene. In the process, as shown on the video, the truck crosses left into an adjacent lane forcing a pickup truck onto the left shoulder. The access ramp to the runaway lane was on the right -- it's an arrester bed, actually.

Curiously, in that video there is no sign of smoke coming from the truck's wheels, which one would expect to see if the brakes were dangerously overheated. In another video, what could be smoke is seen coming from the tractor drive wheels as it blows past a car sitting in traffic just a few yards before the scene of the crash. It could have been just road dust, too; it's difficult to say.

On the maintenance front, the company's (Castellano 03 Trucking LLC, of Houston, Texas) carrier safety profile shows it incurred 30 violations since the fall of 2017, 10 of them brake related. Those brake citations include one count of (393.45), "Brake tubing and hose adequacy;" three counts of (393.45(b)(2)), "Brake hose or tubing chafing and/or kinking;" three counts of (393.47(e)), "Clamp or Roto-type brake out-of-adjustment;" and three counts of (393.53(b)), "CMV manufactured after 10/19/94 has an automatic airbrake adjustment system that fails to compensate for wear" (aka automatic brake adjusters or automatic slack adjusters.)

The rap sheet also includes two citations related to its drivers' ability to speak and understand English: one count of (391.11(b)(2)), "Driver cannot read or speak the English language sufficiently to respond to official inquiries;" and one count of (391.11B2S), "Driver must be able to understand highway traffic signs and signals in the English language." While it's pure speculation on my part, I wonder if the driver, who was said to require an interpreter during his police debriefing, couldn't read the overhead runaway ramp signs and therefore understand that he had just driven past his last hope of salvation.

Driver Rogel Lazaro Aguilera-Mederos  -  Lakewood Police Department

Driver Rogel Lazaro Aguilera-Mederos

Lakewood Police Department

The driver, Houston-based, 23-year-old Rogel Lazaro Aguilera-Mederos, is a U.S. Permanent Resident from Cuba, here legally with a green card. He has no known criminal record, police say, and there was no evidence that Aguilera-Mederos had alcohol or drugs in his system at the time. The Lakewood County police spokesperson, Ty Countryman, is quoted in several TV news reports saying investigators do not believe the crash was intentional. Aguilera-Mederos now faces at least four charges of vehicular homicide and reckless driving related to the crash. Published reports indicate Aguilera-Mederos told investigators that his brakes failed while driving down the hill.

That's pretty well where the facts end at this point in the investigation. Experts will no doubt conduct a forensic analysis of the truck's brakes and dig much deeper into the driver's background, including his experience, training, etc. They will also be looking at the company, Castellano 03 Trucking, LLC. The history of violations noted above along with others detailed in its Safety Measurement System profile of the five-truck fleet don't paint a picture of a very responsible motor carrier.

With that said, I wonder where federal regulators were on this one? Castellano's vehicle out-of-service rate, 23.1%, is 2.4% above the national average, so it's not exactly a stand-out. But how can a fleet with just five trucks run up 17 violations from 19 roadside inspections in less than two years without attracting a little attention?

Mountain Driving

Screen capture from a video shot by a motorist of the alleged crash truck driving past a runaway ramp, minutes before the crash.  -

Screen capture from a video shot by a motorist of the alleged crash truck driving past a runaway ramp, minutes before the crash.

A low percentage of my 2 million or so miles of experience was in the mountains, but I'd say I've navigated such grades a few hundred times – California's Grapevine, the hill on I-80 east of Salt Lake City, Wolf Creek Pass, British Columbia's Coquihalla Highway, Kicking Horse Pass, BC's Hope-Princeton Highway, Crowsnest Pass and countless trips down some of those evil, steep, two-lane hills in Western Pennsylvania and West Virginia. While I have had a few moments on some of those hills (I know all too well what hot brakes smell like), I have never had to use a runaway truck ramp.

I have seen them in several forms in various places around the country. They range from side exits from the highway leading to steep upgrades designed to slow to the speed of the truck, to arrester beds filled with soft gravel, dirt or sand laid alongside the travel lanes of the highway. The one on I-70 in Colorado was the latter type. The truck wheels are supposed to sink into the soft gravel and slow the truck. It must be a rough ride. Clearly the driver in Colorado didn't understand the purpose of a runaway ramp.

I think it's safe to say that further investigation will reveal this driver had little or no mountain driving training. He hails from Houston Texas, which is flatter than pee on a plate. Even if they had wanted to, no driving school in that part of the country could have prepared him for the likes of the grades he would face in Colorado's High Country. In fact, there are very few places in the U.S. where drivers can get mountain driving training.

The CDL manual from Texas, for example, has five sub-sections on mountain driving, including braking techniques, descriptions of brake fade and how to "select a safe speed." Without a big hill to practice on, those words ring rather hollow. For what it's worth, Pennsylvania and Colorado have the same 1.5 pages on mountain driving – but 2.5 pages on the hazards of distracted driving. Take from that what you want.

Google Earth screen grab of the far end of the 2,000-ft long arrester bed runaway truck ramp on I-70 near Lakewood, Colorado. 

Google Earth screen grab of the far end of the 2,000-ft long arrester bed runaway truck ramp on I-70 near Lakewood, Colorado.

A friend of mine, Andy Roberts, runs one of the best truck driving schools in Canada, Mountain Training Institute, in Castlegar, British Columbia. The school is surrounded by mountains, and the only way in or out of town is up or down some very big hills. He offers a mountain driving program, and is, in my opinion, an expert on the subject.

Roberts told me most schools pay lip service to the subject, because the instructors probably haven't had the mountain driving experience, or they are just teaching the students to pass the road test in their jurisdiction, which probably doesn't have a mountain upon which to test the students.

"You can teach theory, but how useful is that?" he asks. "We teach students to come down the hill in a gear that doesn't require service brakes. The other train of thought is to use the same gear going down the hill that you'd use to climb it, but that doesn't always work because the driver maybe didn't come up the hill first."

The other problem with that theory, Roberts says, is today's big high-torque engines are capable climbing some hills at a pretty good speed – faster than he's comfortable with in a long descent.

MTI's mountain driving course teaches proper procedures for ascending and descending long mountain grades, including methods to complete difficult downhill downshifts when the wrong gear has been selected for descending a grade, as well as methods for identifying sharp curves ahead of time and proper procedures for dealing with them. Students also learn how to choose the correct gears for downgrades and anticipating grade changes. It's a four-day course with three days of on-road instruction.

Pretty safe to say Aguilera-Mederos had nothing like that kind of training. In fact, one of his friends told a TV station that Aguilera-Mederos was thrilled when he was hired by Castellanos 03 Trucking just two weeks before the crash, because the new job allowed him to drive truck outside of Texas, which meant more money.

Brake Maintenance

I would not be at all surprised if brake condition was found to be a contributing factor in this crash. The trip between the Eisenhower Tunnel and the crash site is about 50 miles – and it's downhill all the way. It's not a constant grade, mind you, but the elevation drops nearly 5,000 feet over that distance in several steps, some steeper than others. If the driver was not an experienced mountain driver, his brakes would likely have been pretty warm by the time he got to the crest at Overlook. If his brakes weren't properly adjusted, some of them could have been hotter – and thus less effective – than the others, leading to the better adjusted brakes doing most of the work and thus heating up even faster.

Back in my day, drivers often adjusted their own brakes or had them set up regularly by a pro before venturing to higher altitudes. This was in the days before self-adjusting brakes were mandated. A 9/16s wrench was a driver's best friend in those days. Today, I think few drivers even give their brakes a second thought, despite being required to inspect them each day.

We won't know anything about the condition of the brakes on the crash truck until they are inspected – and they will be. Post-crash photos show the trailer wheels are still in decent shape, though the tractor wheels look they have been through Hell and back. But experts are able to come to firm conclusions about the pre-crash condition of the brakes despite their present condition.

One thing is certain in this case: The brakes didn't fail – they were overburdened. With any truck air-brake system, the fail-safe position is the brakes are applied. If there's a loss of air pressure, the spring brakes will apply. There are two such systems on truck, the primary and secondary. In the highly unlikely event one suffered a loss of air pressure, the other would continue to function.

But even if there was a loss of pressure in one system and the spring brakes did apply, there would likely not be enough application torque to make a significant difference in the truck's braking capacity. The brake drum expands outward away from the force being applied by the brake shoes, rendering the brake ineffective. If all his wheel-ends were in such a state, the outcome would have been inevitable. 

Driver Experience

It has not been reported how long Aguilera-Mederos has been driving or how long he has had a CDL, but he would have no more than two years of experience driving outside of Texas in places like Colorado. His level of training and experience will surely come out in the investigation, but again, I wouldn't be surprised to learn that lack of experience played a role in this crash.

The problem is, experience isn't required to drive a truck, even in places like Colorado, where I would call it a necessity. Based solely on my experience, when a driver can feel the brakes beginning to show signs of fade, it's time to pull over. Even if you already partway down the hill and the pedal starts feeling different, there's still enough brake there to stop in most circumstances.

I know that feeling, and it’s genuinely sickening. Unfortunately, there are no guidelines or references to draw on for how much brake you have left or how long it will take to stop. It varies with the weight and speed of the vehicle and the steepness of the grade. That's why it's critical that drivers don't fly over the top of the hill and start down the other side without slowing. Yet hardly anyone does that these days. They just flip on the engine brake and continue at highway speed.

In most cases, nothing bad happens. But I think we have been lulled into a luxurious sense of security with modern equipment. It is, however, not infallible. Drivers should be slowing to 40 or 45 mph on these grades – not because they have to (like in the old days), but as a safeguard against a possible problem.

Speed limits for trucks over 30,000 lbs are posted at 45 mph. A sign advises drivers there's a runaway ramp 2,000 feet ahead. 
 -  Google Earth screen capture

Speed limits for trucks over 30,000 lbs are posted at 45 mph. A sign advises drivers there's a runaway ramp 2,000 feet ahead.

Google Earth screen capture

Aguilera-Mederos faces four counts of vehicular homicide and a reckless driving charge. According to a story in the Denver Post, prosecutors only have to prove that he acted recklessly to convict him on those charges.

"For this to stick, the prosecution is going to have to show that he knew or should have known that something was wrong and he ignored that," said Jacob Martinez, a Denver defense attorney who handles traffic cases, the paper reported.

He made his first big mistake by not stopping at the first sign something didn't feel right. He sealed his fate when he failed to pull off at the truck runaway ramp a few miles west of the crash scene. Video captured by a passing motorist shows he was in the right lane and could have used the ramp, but instead he blew right by it at a reported speed of 80 mph.   

"It doesn't matter if it's a semi-truck or a smaller hatchback, you are responsible for that vehicle as it drives on the roadway," said Lakewood Police spokesman Ty Countryman.

Witnesseses quoted in several instances say they saw Aguilera-Mederos looking wide-eyed and terrified as he roared down the hill. I'm sure he was. But why the heck didn't he get off at that runaway ramp when he could?  

In 2012, Jim wrote about the role of brakes in two other highly publicized truck crashes in this blog post, "Truck Brakes Don't Fail by Themselves."

About the author
Jim Park

Jim Park

Equipment Editor

A truck driver and owner-operator for 20 years before becoming a trucking journalist, Jim Park maintains his commercial driver’s license and brings a real-world perspective to Test Drives, as well as to features about equipment spec’ing and trends, maintenance and drivers. His On the Spot videos bring a new dimension to his trucking reporting. And he's the primary host of the HDT Talks Trucking videocast/podcast.

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