Chapter 30 of the General Laws is hereby amended by inserting after section 38 the following section:-
Section 38A. Contracts for road, bridge, water and sewer projects awarded as a result of a proposal or invitation for bids under chapter 7C, section 11C of chapter 25A, section 39M of this chapter and sections 44A to 44H, inclusive, of chapter 149 shall include a price adjustment clause for each of the following materials: fuel, both diesel and gasoline; asphalt; concrete; and steel. A base price for each material shall be set by the awarding authority or agency and shall be included in the bid documents at the time the project is advertised. The awarding authority or agency shall also identify in the bid documents the price index to be used for each material. The price adjustment clause shall provide for a contract adjustment to be made on a monthly basis when the monthly cost change exceeds plus or minus 5 per cent.