Elsewhere in the thread, Cruise's co-founder indicates that they're using the old-school mechanical automation method: actuators on the brake, wheel, and thrott

Elsewhere in the thread, Cruise's co-founder indicates that they're using the old-school mechanical automation method: actuators on the brake, wheel, and throttle. Most cars with active cruise control don't comply with any standard - while the commands to accelerate, decelerate, or steer may be available over a CANbus which is exposed on the OBD-II port, there's no standard like there is for OBD-II diagnostic information and the protocols are often obfuscated or encrypted (either for "security" or manufacturer protectionism).