1.  Except as otherwise provided in subsection 2, all highways constructed under the provisions of this chapter shall be constructed in such manner as to provide for sufficient and permanent drainage and of such materials as to insure, so far as reasonably may be done, considering all of the circumstances, permanent wearing qualities and to provide against excessive maintenance cost. Regard shall always be had to the character and quality of the traffic to be accommodated and the interests of the public to be served.

2.  The Department shall ensure that the use of any recycled aggregate, recycled bituminous pavement or recycled rubber from tires, or any combination thereof, in any project for the construction, reconstruction, improvement, maintenance or repair of a highway is not restricted unless scientific evidence satisfactory to the Department clearly indicates that the use of the recycled aggregate, recycled bituminous pavement or recycled rubber from tires for that project compromises the soundness of the project.