13.—(1) An undertaker executing street works in a street with special engineering difficulties shall, where a plan and section have been settled, execute the works in accordance with the plan and section as settled or, if each of the relevant authorities agrees to the modification of the plan or section, in accordance with them as so modified.
(2) If an undertaker fails to comply with sub-paragraph (1) he commits an offence and is liable on summary conviction to a fine not exceeding level 3 on the standard scale.