Me. Stat. tit. 23 § 1117
The Commissioner of Transportation shall adopt rules to establish the Adopt-A-Highway Program that permit business organizations and nonprofit community organizations to participate in litter control and beautification activities on all state highways and town ways. Notwithstanding any other provision of law, the rules adopted by the commissioner may permit the erection of signs to identify participating organizations, as long as the rules establish permissible dimensions for the sign. Rules adopted pursuant to this section are routine technical rules as defined in Title 5, chapter 375, subchapter II-A. The State, municipalities, the Maine Turnpike Authority and their employees are not liable to any person for damages arising out of any activities resulting from an Adopt-A-Highway Program. [1999, c. 152, Pt. G, §1(AMD).]
23 M.R.S. § 1117