As cars become more like home appliances and consumers become less and less involved with the way cars work, the risk of problems such as forgetting to turn off the engine is only increasing. Automakers consider the electronic code transmitted from the key fob to the ignition system to be the digital equivalent of a physical key, so when the driver presses the button to turn off the car, the code is erased from the start system. Seven years ago, the Society of Automotive Engineers (SAE) proposed a series of beeps to alert drivers that their cars were still running without the key fob in or near the car, and in some cases, to turn off the engine automatically. Older ignition systems, as found in most cars on today's roads, require that the car be placed in park before removing the key.
This would make it easy to violate this regulation if the car cleared the start code as soon as the key fob was too far away. It can even happen on non-hybrid vehicles, since many cars today have very quiet engines that are almost inaudible at idle. A thief can use a radio relay to make the car think that the remote control is nearby, then start it and leave. To avoid this, automakers have designed their cars to stay running so that they can argue that the key cannot be removed before the car is put into park.
There have been reports of cars moving away due to drivers not shutting down the engine with the car still running or in reverse. Keyless cars are a convenience found in millions of vehicles today, and are appreciated by owners who no longer have to fumble with car keys. However, it is important for drivers to remember to turn off their engines when they leave their vehicles.