Driver fatigue is one of the major killers on the road, alongside alcohol and speeding, which is why it's so important to treat drowsy driving in the same way as drink-driving to improve road safety and save lives. This state-of-the-art technology could help police identify drowsy drivers in road accidents as well as assist employers in assessing fitness for duty.
Having an accurate blood test for fatigue could be a valuable tool for law enforcement. However, it wouldn't preclude driver responsibility or prove that a crash was caused by driver fatigue. Moreover, while the key to securing a prosecution would be to agree on a threshold to indicate tiredness or the minimum sleep required to drive safely, more must be done to reduce deaths caused by drowsy driving rather than simply penalizing drivers.
There's a 50% chance that at least two US states will first disallow human-driven vehicles on public roads by 2073, according to the Metaculus prediction community