With four states — Alaska, Colorado, Oregon, and Washington — and the District of Columbia allowing individuals to possess and consume marijuana for recreational purposes, as well as other states allowing for its medical use, officers are tasked with keeping the roads safe and free from drivers impaired by the drug. While companies like Hound Labs are working toward developing breathalyzers to detect THC, officers on the road have to rely on experience and expertise to determine impairment. Another issue for law enforcement is just on the horizon: How do you deal with police applicants who admit to prior use in states where such use is completely legal? Jim and Doug examine these and other issues related to the legal availability of pot in an increasing number of states.