Reference Line. Add the following: “For paving at structures, including approaches, the use of a taut reference line will be required to insure satisfactory paving results for all structures pavement courses. The substitution of a “ski”, “floating beam” or other type of moving reference will not be permitted on asphalt pavers used on structures pavements. For mill and repaving work, automatic HMA pavers shall be equipped with a moving reference of at least 30 feet in length, i.e., grade averaging system. Physical reference for grade, slope and profile control shall be from the milled surface in front of the paver and the freshly laid hot mat in back of the paver. The Engineer may approve another grade control system, as long as it meets the above criteria.”
