The commissioner of the Department of Transportation may enter into agreements with the owners of advertising devices not prohibited under this chapter and lawfully erected and maintained in adjacent areas, or with the owners of the real property on which the advertising devices are located, providing for the control of vegetation on the right-of-way in the vicinity of the advertising devices to ensure their visibility from the highway. The agreements shall provide that:
Minn. Stat. § 173.171
1981 c 294 s 3