Following a smattering of recent high-profile attacks, the National Highway Traffic Safety Administration is taking a hard look at vehicular cybersecurity. In a 22-page document (PDF), the NHTSA outlines its voluntary best practices for automakers going forward. Chief among the guidelines is using a layered approach to security, so that even in the event of a successful attack that “vehicle systems take appropriate and safe actions.” Meaning, a car’s computer shouldn’t put the driver at risk just to fend off an intruder. The agency also suggests designing connected systems with cyber security in mind from the outset. “If a cyber-attack is detected, the safety risk to vehicle occupants and surrounding road users should be mitigated and the vehicle should be transitioned to a reasonable risk state,” the paper reads.