Avoiding Truck Underride Crashes: Useful tips

This article is written to give car drivers an idea of what they can do instead of blaming the trucks for not having a proper underride bar.

BHPian chaitanyakrish recently shared this with other enthusiasts.

Avoiding Truck Underride Crashes

Introduction:

All the bad driving videos are taken from Instagram,X,Youtube and credits are for the respective owners for taking extra risk to let us know, how not to drive !!

All the videos where the ideal scenarios are demonstrated are from my dashcam.

What is an underride ?

An underride crash happens when passenger cars slide under the trucks due to their height difference under the following conditions :

1. Underride bar is not as per standards

2. There is no underride bar at all

3. The speed of the car is very high even for a built to standard underride bar to withstand the impact.

Underride crashes can happen at the side of the truck and rear of the truck as well and even on the front as well.

It’s very essential for trucks to have built to standard underride bars but its a distant dream. Until its fitted to all trucks as per standards, let’s assume none of them have it.

Why is an underride crash dangerous ?

Underride crashes can cause severe injuries and often fatalities as during the impact would be directly at the windshield with an poorly built underride bar or non-existent underride and completely bypassing the crumple zones, airbags etc.

A pillars of car are not built to withstand such a large force like a crumple zone and passengers in front would directly hit the truck causing severe upper body injuries and most often fatal.

Observe the crash dummies in this video.

Types of underride crashes

Side underride and rear underride are the major types of underride crashes.

Rear underride:

A full overlap underride

Partial overlap underride

Narrow overlap underride

Side Underride:

Source: IIHS

How to avoid a side underride Crash?

A side underride crash can happen near intersections, so be watchful of turning trucks and maintain sufficient distance.

Front Underride :

Front Underride crashes are possible in a head-on crash with trucks on single carriageway roads. Not all trucks have front underride guards as per standards and its a deadly form of crash as due to relative velocity, the speeds would add up increasing the momentum.

All these crashes show front underride with minimal chances of survival

How to avoid head-on underride ?

Plan overtakes carefully on single carriageway/undivided roads. If in doubt, do not attempt. There are no rewards for excessive risk taking on roads.

Follow the below golden rule of overtaking on single carriageway roads.

Source : Roadkraft

Can an SUV have a better chance of survival in an underride crash ?

Not always as the underride crash is arising out of the height difference between passenger cars and trucks, it is very difficult to find standardized truck sizes in India.

Can the car drivers do anything to prevent having an underride crash ?

Yes, they can. Let’s study the strategies we can adopt to minimize this fatal risk.

Before going for details, let’s see why do underride crashes happen.

Why do underride crashes happen?

There are many reasons for underride crashes and its mostly due to mistakes by smaller vehicles as truck drivers mostly unaware of their presence.

Most common reasons are :

1. Car drivers fail to notice trucks either due to speed or of low visibility conditions like night,rain,fog etc and couldn’t take an evasive action on time.

2. Car drivers tailgate trucks at high speed looking for an overtaking opportunity.

3. Cars got stuck in clusters of vehicles and do not have an exit route.

4. Cars using road shoulder for overtake and suddenly finds a parked truck.

Even the lowest priced car in India is capable of moving faster than the average truck in India. This disproportionate capacity puts smaller vehicles at risk as even though both the vehicles are at speed, trucks has huge momentum due to their mass and they have the clear advantage.

Does speed of car matter?

A high speed underride is more risky however as per tests by ADAC, its unsafe even at low speeds.

Causes for underride crashes:

Lets study the situations one by one. We will see the driving habits which puts us in these risky situations where the risks are high with a low reward.

Full Overlap Underride:

A full overlap underride is possible when a high speed car hits the back of truck either when it is parked on the road shoulder or when the truck is moving slowly on any lane.

Why did the car driver failed to notice the truck ?

1. Car is at Speed

2. Truck is on a curve and not visible until the driver had visibility

3. Distracted Driving

4. Poor Visibility due to fog,rain,night etc.

5. Overtaking using road shoulder

All the above can occur together as well, for example a distracted driver could be at a high speed, tries an overtake using road shoulder and failed to spot a parked truck on a curve at night !!

To hit a moving truck and cause an underride, the truck might be moving slowly on any lane on an upward incline or on a level road and a high speed car didn’t react early and hits the back of the truck and underride it.

Again, the reason for not reacting early could be any of those above.

How to avoid getting into an full overlap underride?

1. Avoid Driving on the hard shoulder

2. Drive as per visibility. We should be able to stop within the road we can see and that should be our speed.

3. Expect slow moving trucks on upward incline roads and change lanes early and don’t wait for the last moment. Note, your high speed car can cruise on the upward incline at 60–80 kmph but at the same time, a fully loaded truck could be at crawling 10kmph speed on the same incline. Observe the wheels of this truck and how slow they’re moving on the incline. This sets up for a high risk scenario for an underride.

4. Apply the same rules for curves on highways as applicable on mountain roads. The farthest point we can see on a curve is called a limit point. We should drive at speed that allows us to stop within the road we can see. Don’t enter curves fast only to find a surprise at the other end of the curve.

Partial Overlap underride is also possible in above scenarios where the driver tries to take an evasive action but unable to do so due to speed and hits the corner of the underride guard.

Partial Overlap Underride:

A partial overlap underride is possible when high speed cars tailgate trucks to perform a close overtake. This is a very high risk and low reward move and it requires utmost co-ordination from all the vehicles involved which is very much unlikely. We cannot expect other drivers to keep us alive on the road.

The bad driving examples are taken from Instagram (Click Here)

This is an Unsafe Overtaking with Tailgating and is an example of a high risk low reward overtake. This type of overtaking trucks closely puts us in a dangerous position and there’s always a possibility of an underride but may not happen everyday due to randomness in life.

The above driving scenario is possible when multiple slow moving vehicles occupy all the available lanes in parallel while they’re overtaking each other.

This forms a cluster of slow moving vehicles behind the trucks and forces the fast moving cars to weave across and go ahead.

But, it's not required to weave across and increase the risk. Always look at the big picture and take steps to reduce risk...

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