Death by design

Christine - humanfactors101.com

Could you be killed by a car tonight?

You’re perhaps thinking that I’m referring to a road traffic accident – as an occupant in a vehicle, or maybe as a pedestrian or cyclist. But there’s another way that you could be killed by a car tonight – YOUR car in fact.  And this isn’t a reference to the Stephen King novel “Christine”, about a car apparently possessed by supernatural forces.

In 2006, Jeanette Colter unintentionally left her car running in the garage. After carbon monoxide from the car’s engine slowly and silently flooded their home, both Jeanette and her husband were poisoned. This may have been the first reported case, but many similar tragedies have been reported since. Let’s look at these from a human factors perspective.

Not-so-Smart keys

These deaths have been attributed to keyless-ignition vehicles inadvertently left running in an enclosed garage. Typically, someone drives into their garage – which can be either attached to or underneath the property – and enters the house taking the smart key fob with them, believing that the car has been shut off. Many victims retire to bed and are slowly poisoned in their sleep.

On 14 June 2018, a Florida resident left a car running overnight in the garage. Two adults and three children sleeping inside the home were evacuated. The Orlando Fire Department reported carbon monoxide levels in the house to be ten times the safe 8-hour level. 

After reading about these cases I was a little concerned, because one of my vehicles has keyless-entry and keyless-start, and our garage is connected to the house. So, technically, this is a mistake that I could make.

Toyota start-stop button humanfactors101.comKeyless-entry and keyless-ignition systems introduce quite a change to the way that we have interacted with our cars for many years, often decades. Instead of a key that is inserted into the ignition, the doors on my Toyota can be unlocked and the engine started/stopped as long as I have the smart key with me (known as the Smart Entry and Start System).

With this new convenient smart-key, it’s possible to do several things that I can’t do with my other vehicle (a VW which uses a good old-fashioned key to start the engine):

  1. I can start or stop the engine simply by pressing the START-STOP button on the dashboard – even if I’m not carrying the smart key on my person (it may, for example, be in a jacket pocket on the rear seat).
  2. I can exit the vehicle, with the engine running, and leave the smart key inside (again, perhaps the “key” is in my jacket pocket on the rear seat). The vehicle may or may not be in Park (P), and the handbrake may be on or off. When idling, the engine is smooth and pretty quiet.
  3. I can leave the vehicle running and take the smart key as far as possible away from the garage, and the engine continues to idle. Once in the house, I can’t hear the engine from any room. As far as I know, the engine will continue to idle until it runs out of fuel (with 138 litres of petrol, that’s going to be a while).
  4. I can stop the engine by pressing the START-STOP button when the vehicle is in Drive (D) or Reverse (R), and exit the vehicle with the handbrake not engaged. This set of circumstances has led to several fatalities, where drivers have been run over by their own vehicle (for example, when parked on an incline) – known as rollaways.

To lock the vehicle, I simply touch a small button on the door handle, as long as the smart key is on my person. I did discover that I cannot lock the vehicle from the outside when the engine is running (whether I have the smart key with me or not). However, I often leave the vehicle unlocked when in the garage.

Here’s a short video from the United States NHTSA (National Highway Traffic Safety Administration) highlighting the dangers of keyless-ignition vehicles:

Applying human factors to this scenario

As we leave our vehicles; whether that’s in the office car park, the shopping centre, or in the garage at home; we’re often thinking about what we’re doing next – that important meeting, the things we need to buy for dinner, or the dog that’s in the house patiently waiting for his walk. With our minds elsewhere in the future, we’re not paying attention to the present, and it’s easy to see how we can walk away from our vehicles with the engine running.

This mistake would be even easier if we are talking on the phone, in a hurry, distracted by children or pets, tired after a long journey, or just so used to engines that are “off” when we have the keys with us on leaving the car. Factors like these often make slips and mistakes more likely. I’ve written about these Performance Influencing Factors previously. Performance Influencing Factors are a key concept in human factors.

Modern technology is also contributing, as vehicle engines are becoming quieter – and some hybrid vehicles may not be running at all when stationary (until the petrol engine kicks-in automatically when the electric battery becomes depleted).

Like many families, we own two cars. In our case, a Toyota with a smart key and a Volkswagen with remote-locking, but a traditional key that is inserted into the ignition barrel. This sometimes leads to minor failures on my part: simply walking up to the VW and touching the handle does not unlock this car; this catches me out frequently.  And I often exit the VW having turned off the engine, but leaving the key in the ignition – as I’m becoming used to the convenience of the Toyota smart key that stays in my pocket. Thankfully both cars are automatics and run on unleaded petrol, so I’m spared some of the potential issues if I owned both a manual and automatic, or a diesel and a petrol. . .

These behaviours are largely due to something called “strong stereotype takeover“. This is when we revert to a more familiar behaviour – one that is often practiced, but incorrect for the current circumstances. For example, if you have moved house recently, you may find yourself driving to your previous home on the journey back from work.

Such behaviours are sometimes referred to as “strong but wrong” behaviours. We are more likely to revert to these familiar habits or behaviours when tired, distracted or under high workload. These strong habits often intrude during behaviours in which we are highly-skilled and therefore do not require much conscious focus (we’re “absent-minded”). Strong stereotype takeover is also more likely when the two tasks or behaviours share several common aspects.

The introduction of keyless-ignitions has created what human factors professionals often refer to as “unintended effects”. When this technology was introduced, the new hazards that were introduced (e.g. vehicle rollaways, theft opportunities, carbon monoxide poisoning) were either not identified, or were ineffectively managed. The design of keyless-ignition systems has fundamentally changed the relationship between the “key” and the ignition. These hazards are in fact new “design features” of keyless-ignition systems. When managing change, the impact of a change on existing controls or the possible introduction of new scenarios and hazards should be considered. Solving one issue may create new ways that people can behave (and sometimes fail. . . ).

Whilst writing this article, I thought of another scenario that had me searching for my vehicle manual. In an emergency, for example in the case of unintended acceleration, or a stuck gas pedal, a traditional key could be used to turn off the engine. However, if you have keyless ignition, would you know how to turn off your engine whilst driving?  The stress of an emergency may impair your judgement.  Your car may be different, but in many vehicles with a START-STOP button, holding down the button for three seconds will turn the engine off in an emergency (noting that this will also disable power steering and make the vehicle harder to maneuver). Simply pushing the button once, as you do normally when stationary, will not work when you’re travelling at speed.

Managing the risk?

Many manufacturers have installed an internal alert that sounds when the driver’s door has been opened with the smart key still in the vehicle, or when the smart key is removed from the vehicle and the engine left running. This internal alert may not be heard by drivers who have exited the vehicle. Some manufacturers have also included an external alert – one that can be heard from outside the vehicle. A more robust solution would be to install an automatic cutoff that kills the engine after a certain period if the smart key is not in the vehicle (some vehicles already have this feature). Or perhaps the engine should turn off if the smart key is a certain distance from the vehicle.

So, what’s stopping me from unintentionally leaving this vehicle running in the garage, as carbon monoxide slowly floods the house?  Well, when I open the driver’s door, my car emits three beeps. These may be easy to miss if I’m engaged in conversation, if the dog on the back seat is excited to be home and barking, or if I’m otherwise distracted. There are no other warnings from the vehicle, even if the smart key is taken into the house, or if the engine continues to run for a long period.

However, I always drive forwards into the garage and I have to walk right behind the vehicle in order to access the door to the house. I’m likely to feel the heat and the pressure from the exhaust pipe as I walk between the rear of the car and the closed garage door. That may help to prompt me that the engine is still running.

After working through a quick human factors analysis of this scenario, I now routinely lock the vehicle in the garage – if it doesn’t lock, then that indicates an issue (such as the engine still idling). I thought about keeping the smart-key on the same fob as my house keys (unlocking the house MAY prompt me that I’ve left the vehicle running), but I leave the house on foot more often than by car, and I don’t want to carry the smart key unless I’m driving (and sometimes I drive the second car – too many keys/fobs!).

Finally, recognising that I’m only human, I installed additional carbon monoxide detectors in the garage and several rooms in the house.

However, these ‘solutions’ only relate to the hazard of carbon monoxide poisoning – it’s still possible for me to turn off the vehicle when in Drive or Reverse and for it to roll as I exit the vehicle. All of my previous automatic cars (with traditional keys) have required me to put the transmission into Park before the key can be removed. If the electronic systems on this vehicle shifted into Park mode automatically when the engine is turned off, this would help to address the rollaway issue. That should be possible on a car with other sophisticated technologies.

Please share this “safety moment” with family, friends and colleagues – and perhaps use this material as way to introduce human factors in design and Performance Influencing Factors into your organisation.

Discussion questions

  1. Can you think of examples of workplace behaviours where a stronger habit could intrude, leading to the “strong stereotype takeover” issue?  Changes in well-established routines often lead to errors. Has new equipment been introduced which could be operated incorrectly due to stronger habits taking over? Does this equipment or a new activity compete with strong habits formed over a long period?
  2. Has your organisation introduced new technology recently that could lead to unintended effects? Does this change create new ways in which people could fail? Why were these unintended effects not identified and managed by the designers or installers?
  3. Keyless-ignition vehicles have changed the relationship between the “key” and the ignition and transmission systems that start/stop and brake the vehicle. Not all consumers understand the implications of this change. Has your organisation changed the nature of a relationship between people and a system, or between different aspects of a system – and what are the potential effects of this change?