The LA Times has an interesting article about problems with Toyota and Lexus cars [1]. Basically there are problems where the cars have uncontrolled acceleration (there seems to be some dispute about whether it is due to engine management or the floor mat catching the accelerator pedal). When that happens the brakes don’t work (due to the vacuum power-assistance for brakes going away when the engine is at full power) and a terrible crash seems inevitable.
There are suggestions that the driver should shift the car to neutral and discussion about how the Toyota gear selection makes that difficult. Some years ago I was driving an automatic car on a freeway at 100Km/h and the engine stalled (due to a problem with the LPG system). I had become used to never touching the gear lever while driving so the possibility of moving the gear lever one notch to neutral didn’t occur to me. With a dead engine in gear the car slowed rapidly which is quite dangerous when surrounded by 100Km/h traffic. Fortunately I was able to swerve into the emergency lane (across one lane of active traffic) before the car slowed much. That was in a relatively controlled environment with a gear shift mechanism that is a lot simpler than that which is common in some of the more expensive cars.
According to Wikipedia the maximum speed limit in the US is 80M/h [2]. It seems to me that Toyota is being irresponsible by selling cars that can sustain 120M/h, while the probability of surviving a crash at 80M/h is quite low, it seems likely to be a lot greater than the probability of surviving a crash at 120M/h. Also if a car is out of control at 80M/h then the driver will have a lot more time to work out how to put the engine in neutral or turn it off – the lower speed will extend the time available by more than 50% because bends in the road can be better handled at 80M/h.
It seems to me that it would be a feature for the car owner to have the car limited to a speed that is not much greater than the speed limit. According to Wikipedia the highest speed limit in Australia is 130Km/h (in NT), but it’s 110Km/h in all places where I have driven. If my car had a governor to limit the speed to 115Km/h and a switch to change the limit to 135Km/h in case I ever drive to the NT then it would not affect my driving patterns (I rarely drive on roads with a 100Km/h limit and almost never drive on roads with a 110Km/h limit) – but it could reduce the probability of things going horribly wrong. Also one thing to note is that last time I checked car tyres sold in Australia were only required to operate safely at speeds below 190Km/h (118M/h), so a Lexus that went out of control at 120M/h in Australia might risk a tyre blow-out – which admittedly would only make things marginally worse.
A governor for the reverse gear would also be a good feature. Some time ago a granny got her foot stuck on the accelerator in a car park and caused serious damage to her car and a parked car – after passing close by where I was standing. I don’t think that there is a real need to do more than 5Km/h in reverse, limiting the speed would give pedestrians a better chance of escaping parking accidents.
One serious problem with some of the Toyota and Lexus vehicles is that it apparently takes 3 seconds to turn the engine off in an emergency! I’ve been driving for almost 20 years and experienced a number of dangerous situations, all of which were essentially resolved (for better or worse) in significantly less than 3 seconds. A 3 second delay is as good as a 1 hour delay for safety critical systems.
Also if the accelerator and brake pedals are pressed at the same time then the brake should take precedence. It seems quite obvious that whenever both pedals are pressed hard then the driver would probably prefer hard braking to hard acceleration.
If you look at industrial machinery (robots, lathes, etc) you will always see big red buttons (or whatever color is used for emergency stop in your region) that are clearly marked and obvious – to the workers and to bystanders. Escalators have less obvious red buttons but they can still be shut down in an emergency. It seems to me that there are potential benefits to having an emergency shutdown button in a car, maybe in a position that is accessible to the front-seat passenger in case the driver is incapacitated. Such a shutdown button wouldn’t do anything extreme such as fully activating the brakes (which would be very bad on a road that has high-speed traffic), but would prevent acceleration (with some sort of hardware control to avoid software problems) and maintain power to the brakes and the steering.
One thing that needs to be considered is that people tend not to do the most logical things when in an emergency situation. It needs to be possible to do whatever is necessary to save your life without any great deal of thought. Pushing a big red button is easy, holding down the “on” button for 3 seconds or even navigating a gear shift to an uncommon setting is a lot more difficult.
It seems to me that there is also an issue of driver training. If putting an automatic car into neutral and cruising to a stop was part of the test for new drivers then the results of such car problems might not always be so bad.
But I don’t expect there to be any serious changes to driver training or car design. People are too accepting of road deaths.
Don Marti has expressed a plan to never buy a vehicle with an automatic transmission because of this issue [3]. But the number of new vehicles being sold with a manual transmission is steadily reducing. An automatic transmission allows better performance (F1 cars have used them for ages), better fuel efficiency (you could never make a manual Prius), a more comfortable ride (the Hybrid Lexus keeps winning the Australian Luxury Car of the Year award), and allows less skillful drivers. Unless Don wants to ride a moped or drive an old car then I expect that he will be forced to get an automatic transmission. Then of course he will still be at risk of other people having car problems (the LA Times article mentions a third party being killed after an out of control car hit them).
Also I expect that the extra safety features that are implemented in luxury vehicles such as the Lexus would save a few lives, they should save enough to outweigh the number that are lost on the rare occasions when the car goes out of control. Other luxury cars such as the Mercedes S class have great safety features and don’t have a history of going wrong in a newsworthy way. A second-hand S Class Mercedes was surprisingly cheap in the UK last time I checked, cheap enough to make it worth considering the importation of one to Australia.
But my solution to these problems is to try and minimise my driving. A 1.5 ton Lexus driving out of control at the maximum speed possible in urban streets won’t do much damage to a 20 ton tram.
