(a) In addition to the operation authorized by Section 551A.055, the governing body of a municipality may allow an operator to operate an unregistered off-highway vehicle on all or part of a highway that:
(1) is in the corporate boundaries of the municipality; and
(2) has a posted speed limit of not more than 35 miles per hour.
(b) In addition to the operation authorized by Section 551A.055, the commissioners court of a county described by Subsection (c) may allow an operator to operate an unregistered off-highway vehicle on all or part of a highway that:
(1) is located in the unincorporated area of the county; and
(2) has a posted speed limit of not more than 35 miles per hour.

(c) Subsection (b) applies only to a county that:
(1) borders or contains a portion of the Red River;
(2) borders or contains a portion of the Guadalupe River and contains a part of a barrier island that borders the Gulf of Mexico; or
(3) is adjacent to a county described by Subdivision (2) and:
(A) has a population of less than 37,000; and
(B) contains a part of a barrier island or peninsula that borders the Gulf of Mexico.