The agency recommends safeguards to block Autopilot engagement on certain roadways and better monitor drivers' attention to the road.

The National Transportation Safety Board has finally issued its analysis of the first fatal Autopilot accident, splitting blame between the Model S driver and Tesla.The report concluded that a truck driver's failure to yield the right of way and the car driver's inattention "due to overreliance on vehicle automation" are the probable cause of the fatal crash early last year in Florida.

The agency further argues that the operational design of Tesla's Autopilot system permitted the car driver's overreliance on automation, permitting the driver to disengage from the driving task for nearly the entire journey. The system also allowed the driver to engage Autopilot on a type of roadway inconsistent with Tesla's safety guidelines.

"System safeguards, that should have prevented the Tesla's driver from using the car's automation system on certain roadways, were lacking and the combined effects of human error and the lack of sufficient system safeguards resulted in a fatal collision that should not have happened," said NTSB chairman Robert L Sumwalt III.

The agency issued several specific recommendations, calling for better monitoring of driver attention and automatic restrictions to ensure automated systems can only be engaged on supported roadways.

Tesla has already implemented a few changes to its Autopilot system to prevent abuse, reducing the delay before issuing a warning/alert when a driver's hands are off the steering wheel. The system also adjusts the alert timing sequence when operating outside of preferred roads.

The NTSB also outlined a few broad suggestions, addressing a need for industry-wide standardization of event data recording and regulations mandating reporting of failure incidents and crashes.

The report will presumably be closely reviewed by automakers and suppliers as companies continue to gradually roll out more advanced automation technologies.