ATD LINES Police Department is responsible for: the protection of life, individual liberty and property protection; the preservation of peace and railway public safety; the prevention of railway crime and disorderly behavior ; the detection and arrest of violators of the law; the enforcement of state, federal and international laws; including ATD LINES rules within the all departments and division jurisdictions; and the provision of public service to the railroad industry and rail line communities.

The function of the ATD LINES Police Department must be broadly interpreted to include many tasks other than the enforcement of laws, security, emergency and disaster management.