In the interest of better roads for all Pennsylvania and an equitable distribution of funds available for highway purposes for use on local roads and streets as related to the burden of highway traffic thereon and the revenues derived therefrom, the General Assembly finds that it is necessary to provide for a permanent allocation of a part of the highway funds among cities, boroughs, incorporated towns and townships, for the roads and streets for which they are responsible, or in townships of the first class for State highways within their respective boundaries, including drainage facilities.