The Usual Suspects: Top 5 Fleet Mechanical Failures

Posted by Reza Tavassoli on 13-Feb-2020 8:00:00 AM
Reza Tavassoli

Suspect line of a police station showing 5 people in the line-up and each person represents on of the top 5 hazards due to mechanical  failures.Our highways are shared by private car drivers and commercial transportation truckers alike. This combination of driver skills and behaviors is an increasingly dangerous mix. Since 2015 there has been an increasing trend in highway fatality numbers. The recent U.S. Department of Transportation’s National Highway Traffic Safety Administration report elaborates on the true meaning of one of the smaller statistical causes, mechanical failures. While the impact they indicate is anything but small, the good news is that it is far more preventable than currently practiced.

According to a Crash Stats Report, 94% (or 2,046,000) of motor vehicle accidents are attributed to decisions made by one or more drivers. In that same causality report, mechanical failure is only attributed to 2% (or 44,000) of accidents. With such a minimal causality ratio for accidents, why focus on ones caused by mechanical failure? Because, as noted by the NHTSA, that 2% figure is inaccurate; “the vehicle related critical reasons were mainly inferred through external visual inspection of the vehicle components. The related statistics may not, therefore, be representative of the role of the other internal vehicle-related problems.” In a nutshell, mechanical failures are a bigger problem than the historic data collection methods suggest.


Top 5 mechanical failures that cause accidents:

A) Critical Causes

Failure #1: Tires/WheelsWorn out truck tire piece in the middle of the highway being a driving hazard for other vehicles.

A recent Crash Stats report indicates, “the tire problem accounted for about 35 percent (±11.4%) of the crashes” where vehicle failures were the cause of the crash.

Two of the most common problems from tires are blowouts and worn tires.

1. Tire blowouts. Blowouts happen for any number of reasons, including a tire suddenly bursting under pressure from worn out, under- or over-inflation, tires being punctured by junk in the road, or even rapid, extreme temperature changes. Blowouts quickly reduce a driver’s ability to control the vehicle.
2. Worn tires. Time on the road contributes to wear and tear on tire treads. This compromises tire grip—particularly in inclement weather (snow, rain, etc.). making them more likely to slip, take more distance to brake, and less responsive due to their weak grip on the road, all of which contribute to accidents.

Failure #2: BrakesDamaged transit city bus from an accident caused by poor brake maintenance.

     The crash stats report tells us, “brake-related problems… accounted for about 22 percent (±15.4%)” of crashes…” The most common being rear-end collisions. Bad brakes are a major factor in the driver to stop in time to avoid ramming right into the vehicle in front.

Frequent factors contributing to brake-related accidents include:

  • Faulty/Worn Brake Lines. Leaky brake lines allow brake fluid to drain away, rendering brakes useless.
  • ABS Malfunctions. An Anti-lock Brake System (ABS) is designed to prevent the wheels from locking up when the brakes pressed hard. This minimizes slipping and loss of control. Any problems ABS can increase slipping.
  • Worn Brake Discs & Pads. The braking assembly in your car wears out with time and use. This wearing down makes it harder to stop your vehicle, resulting in longer stop distances and increased accident risks.

Failure #3: Steering, Suspension, Transmission…Frustrated fleet vehicle driver biting the steering wheel because of steering, transmission or suspension failures.

The third most critical cause of accidents cited in the NHTSA report was a combination of “steering/suspension/transmission/engine-related problems.” They accounted for only 3 percent of the crashes cited in the report, but this is where the results get interesting. One of the reasons these issues are seldom cited as the definitive cause for an accident is that they’re harder to identify post-crash. Blown tires & worn brakes are easy to spot, but damage to the suspension caused by wear and tear is harder to sort out from the damage incurred in the crash.

Problems with your steering or suspension may diminish control over your vehicle at inopportune moments. A poorly functioning transmission or engine might prevent you from quickly accelerating when most needed. Regularly scheduled maintenance is a must in minimizing steering and suspension issues that could cause a crash. The Preventive Maintenance module of your FMS should alert you to when your vehicle’s due for a full inspection, and it will also hold information from previous maintenance calls that you can share with the mechanics to help focus repairs where most needed. On this point, it’s always important to get a clear report in your FMS so you know if there are any issues with your steering, suspension, transmission, or engine. An OBD-II system check should be able to give you error codes of varying degrees of importance and the mechanic can add these items, as well as any that have been repaired to the report. Ask us how SM2-Maintain can help you with this.


B) Additional Causes

The previous three causes for road accidents are the most reported ones when it comes to vehicle failures. However, that still leaves about 40% of vehicle-failure accidents with unspecified causes. The NHTSA report lumps these into an unknown mechanical failure grouping without much break down. The common factors in them all are that they affect the driver’s field of vision and reaction times.  At this point in time, the responsibility of catching these before they become problematic mostly lies in the hands of the driver. He/she must keep track of them and report them for corrective maintenance. While some vehicles may have on-board computers that can capture and notify these issues, it may still be a while before the becomes standard. Here, a fleet manager would do best to train their drivers in reporting the incidents and keep extra detailed notes in their preventive maintenance systems. Ask us how SM2-Maintain can help you with this.


Failure #4: Headlights/TaillightsMan changing blown bulb in headlights of a fleet truck.

It becomes much harder to see other vehicles on the road in low visibility conditions, such as nighttime, foggy roads, or during storms. Headlights and taillights increase visibility, showing you more of the road, and helping other drivers to better see your vehicle. A broken taillight makes your truck less visible in poor weather and could increase the chances of getting rear-ended or sideswiped.

Even on a clear day, vehicle lights are important. Turn signals show other drivers you’re preparing to change lanes or turn, and brake lights tells them you’re stopping or slowing down. Working lights alert other drivers of your impending actions and gives them the ability to drive safer and tell others of your actions. E.g. When a car brakes in front of us, we do too, because we see their lights first.


Failure #5: Windshield WipersFaulty windshield wipers showing frosted front windshield of a fleet city transit bus.

Never underestimate the importance of your windshield wipers. When it’s raining hard, snowing, or getting the dirty spay from other cars in the spring, visibility is greatly reduced. Using hazard lights may not always be an option if they are illegal in your state (e.g. Florida). You have to stick with your windshield wipers to clear rain and dirt from the window, so you can see where you’re going a bit better. So, keeping them in good working order is very important. Check with your vehicle manufacturers or mechanics for the best blades for you.

Worn out wiper blades leave streaks that continue to block your sight, and those are simpler to replace. However, if the wiper motors break, the sudden loss of vision may be alarming enough to cause an accident. Check your windshield wipers as often as possible, depending on the conditions where you drive. Keeping spares is always advisable. Also, be sure to check your wiper fluid and top it off whenever possible with the type that works best for the season. Finally, keep track of when you make blade changes and fluid replacements in your maintenance logs to help your fleet manager with their planning.


Prevention is the best medicine

Remember, while mechanical failures are not always be detected, much less cited as the critical reasons for an accident in most cases, they can still be contributing factors. The best protection is to plan and adhere to a preventive maintenance program and to drive carefully. Unfortunately, accidents may still happen to the best drivers in the most well-maintained vehicles. To learn more about the ways to minimize preventable accidents caused by mechanical failure, please contact us about your specific challenges. We are always ready to help and very confident SM2 Maintain will be a solution for your needs.


#safety #fleetsafety #preventivemaintenance #fleetmanagement #dedicatedtosafety


Topics: fleet maintenance, preventive maintenance, safety, Mass Transit