Meanwhile, General Motors CEO Mary Barra told members of the House Energy & Commerce Committee during a hearing on its ignition switch recall that "the push-button start is something we're evaluating putting across the portfolio."
As the various GM recalls have underscored, keyed ignition systems can inadvertently be jostled out of position. When that happens, a vehicle can shut off, causing the driver to lose control. But safety is just one reason why manufactures are looking for alternatives.
"Real estate is at a premium," Sullivan said, noting that automotive designers and engineers are trying to clear space to squeeze in more technologies.
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Still, keyless ignition systems aren't a panacea. When it was struggling to deal with its unintended acceleration problems five years ago, Toyota discovered that some motorists were unable to stop vehicles equipped with push-button starters. It eventually advised owners to "firmly and steadily" push the button for at least three seconds to turn off the engine.
Meanwhile, there is growing concern that hackers might be able to crack the code and start stealing cars equipped with keyless entry and ignition systems.
The National Highway Traffic Safety Administration has been studying the technology, and could issue national standards next year.