In the race to develop self-driving cars, Tesla's Elon Musk appears to be leaving a key technology on the table, raising questions about how fast the electric-car maker will be able to create a fully self-driving system and about safety.
The technology is LiDAR, or light ranging and detection laser system, a system that works like radar only using laser beams.
Musk, one of the most closely watched executives in the auto industry, believes he can build self-driving and semi-autonomous cars without relying on LiDAR. Instead, Tesla has looked to cameras and radar — without LiDAR — to do much of the work needed for its Autopilot driver assistance system.
That's in contrast to other automakers and tech companies rushing to develop autonomous cars — Ford, General Motors and Google's Waymo, for instance — that are betting on LiDAR.
In a posting on Medium last year, Kyle Vogt, CEO of GM's Cruise Automation, wrote that "LiDAR sensors contribute to the redundancy and overlapping capabilities needed to build a car that operates without a driver, even in the most challenging environments."
Many industry watchers believe LiDAR is an essential part of developing safe self-driving systems. Lidar, also known as light detection and ranging, is typically seen as a device spinning atop an autonomous vehicle.
"I think you absolutely need all three types (cameras, LiDAR and radar) because each one has strengths and weaknesses," said Sam Abuelsamid, an analyst with Navigant Research.
Abuelsamid pointed to a camera's ability, for instance, to recognize objects but its difficulty in seeing in certain dark and light conditions. LiDAR, on the other hand, bounces lasers off an object to create an image, potentially avoiding the lighting issue even as rain and snow could limit its effectiveness.
Because of those strengths and weaknesses, each technology offers a level of redundancy, which Abuelsamid and others believe is needed.
"Tesla's trying to do it on the cheap," Abuelsamid said. "They're trying to take the cheap approach and focus on software. The problem with software is it's only as good as the data you can feed it."
Tesla's approach on LiDAR has raised questions in light of some recent crashes involving cars in Autopilot mode, although it's not clear that the technology would have made a difference.
Tesla declined to comment on the subject.
David Liniado, Cox Automotive's vice president for new growth and development, has experience with Tesla's Autopilot system because he drives a Tesla, the Model X SUV.
“I think it’s the safest cruise control that there is, their Autopilot, and I think it’s a game changer," Liniado said.
He, too, believes cost is likely what motivated Musk's comments on LiDAR.
With prices estimated as high as $75,000 per vehicle in recent years, it's not difficult to see why. But those in the industry say prices will come down dramatically in the future.
Mitch Hourtienne, director of business development for lidar startup Cepton, predicted at a conference this month in Ypsilanti, Mich., that the company eventually could get its price below $200.
Lower prices are important because consumers will not necessarily be willing to pay extra for LiDAR, Hourtienne said, noting that carmakers must sell consumers on the technology's benefits regarding safety.