Another potential source of funds, especially for local road needs, is developer fees. The advantage of such fees is that they have the potential to assign costs to the persons that create the need for new roads. Of course, these fees get passed on to the users of such developments.
The problem with such fees, especially if they relate to arterials leading into and out of local developments, is that it is very difficult to assess up front what the true future increases in traffic will be as a result of a given development. It is also difficult to administer such a system.
Another potential problem is that the system will be used not just to recover the actual costs of greenfield development, but to penalize such developments in order to promote a social agenda related to center city urban development and increasing the viability of mass transit. Nonetheless, such fees, which are already charged for local roads in many jurisdictions, are an option, especially for city and county road needs.