(a) All State highway projects shall be performed under the supervision of the Administration and subject to its approval, in accordance with plans and specifications prepared by the chief engineer and approved by the Administration.

(b) To receive the full benefit of competitive bidding, the Administration, whenever practicable, shall separate major construction projects into two or more smaller contracts.

(c) The Administration shall include in construction and maintenance contracts a requirement that a contractor protect roadside trees to the maximum extent practicable in the performance of the contractor's duties under the contract.