By David Shepardson
WASHINGTON (Reuters) - U.S. regulators has found no evidence of any defects in Tesla electric cars after investigating the death of a man whose Model S collided with a truck while he was using its Autopilot system, the first fatality involving semi-autonomous driving software.
The U.S. National Highway Traffic Safety Administration said on Thursday it will not seek a vehicle recall after conducting a six-month investigation. The crash drew enormous attention and raised questions about the safety of systems that can perform driving tasks for long stretches with little or no human intervention.
The regulator's decision is seen as a boost to automakers racing to get vehicles that are nearly self-driving or fully autonomous on U.S. roads in the next few years.
U.S. Transportation Secretary Anthony Foxx told reporters that drivers have a duty to take their obligations seriously and automakers must explain the limits of semi-autonomous systems.
"The (auto) industry is going to have to be clear about what the technology does and what it is does not do, and communicate it clearly," Foxx said.
Joshua Brown, a 40-year-old former Navy SEAL from Ohio, was using the technology in his Model S before he collided with a truck near Williston, Florida, last May and was killed.
NHTSA said in a report that Brown did not apply the brakes and his last action was to set the cruise control at 74 miles per hour (119 kph), less than two minutes before the crash.
The agency said Brown "should have been able to take some action before the crash, like braking, steering or attempting to avoid the vehicle. He took none of those actions."
Tesla Motors Inc <TSLA.O> said "the safety of our customers comes first, and we appreciate the thoroughness of NHTSA’s report and its conclusion."
Jack Landskroner, a lawyer for Brown's family, said they plan to evaluate all of the information from government agencies investigating the crash "before making any decisions or taking any position on these matters."
Tesla in September unveiled improvements to Autopilot, adding new limits on hands-off driving and other features that its chief executive officer said likely would have prevented a fatality.
NHTSA said in the report that drivers could be confused about whether the system or the driver is in control of the vehicle at certain times. The agency also said its decision to close the investigation was not contingent on the software improvements announced in September.
NHTSA also said an analysis of Tesla data suggested the vehicle crash rate fell by 40 percent after the installation of its Autosteer lane-keeping function.
The investigation was closely watched by automakers who are introducing semi-autonomous features and pursuing fully self-driving vehicles. Brown's death raised questions about whether regulators have the authority to oversee rapidly developing vehicle technologies.
In October, CEO Elon Musk said all new Tesla models will come with an $8,000 hardware package to enable them to be fully self-driving. By the end of 2017 a Tesla should be able to drive in full autonomous mode from Los Angeles to New York "without the need for a single touch" on the wheel, Musk said.
Rival automakers have said they expect to be able to field autonomous driving capability by around 2020.
The U.S. National Transportation Safety Board, which is also probing the crash, said there have been no reported incidents in the United States involving a Tesla in autopilot mode that resulted in fatalities or injuries since a Pennsylvania crash in July injured two people.
Tesla has introduced restrictions on Autopilot after concerns arose that the system lulled users into a false sense of security through its "hands-off" driving capability. Drivers are temporarily prevented from using the system if they do not respond to audible warnings to take back control of the car.
(Editing by Jeffrey Benkoe)