The road commissioner may, but is not required to, supervise any work done under any permit issued under the provisions of this chapter, in which event the permittee shall pay the reasonable cost of such supervision to the road commissioner, but no cost of supervision shall be charged by the road commissioner to any public corporation, provided, however, this section shall not operate to prevent charges made pursuant to Government Code Section 6103.6.
Ca. Sts. and High. Code § 1464