The county board of any county may also use motor fuel tax funds allotted to it for placing, erecting, and maintaining signs, or surface markings, or both to indicate officially designated bicycle routes along county highways. In addition, the county board of a county with a population over 500,000 may also use motor fuel tax funds allotted to it for the construction and maintenance of bicycle routes or paths, shared-use paths for nonvehicular public travel, and sidewalks within the county, including along State highways by agreement with the Department.
605 ILCS 5/5-701.13