This paper presents an update on the implementation of a touch-based optical sensor (TTT sensor) for monitoring the alcohol concentration in the driver of a vehicle. This novel sensor is intended to improve driver safety by providing a non-intrusive means of notifying a driver when their blood alcohol concentration may be too high to operate a vehicle safely. Details on implementation of the MARK2 system are presented along with updates on principles of the MARK3 version currently under development. Laboratory validation of the MARK2 system on standard calibration standards are presented along with discussion of next steps in validation of the technology. Updates on the demonstration vehicle implementation are also provided along with lessons learned in the implementation of the human-machine interface aspect of the design.