Recognizing that the Transportation Equity Act for the 21st Century establishes a national "Scenic Byways" grant program and a new apportionment program called "Transportation Enhancement Activities," the department of transportation shall place high priority on obtaining funds from those sources for further development of a scenic and recreational highways program, including enhancement projects on the designated scenic and recreational highway system. The department shall consider the use of the designated system by bicyclists and pedestrians in connection with nonmotorized routes in the state trail plan, and the state bicycle plan which are also eligible for TEA-21 funding. Appropriate signage may be used at intersections of nonmotorized and motorized systems to demonstrate the access, location, and the interconnectivity of various modes of travel for transportation and recreation. For the purposes of leveraging national scenic byway planning grant funds, the commission may designate eligible state highways as scenic byways on an interim basis.