State court proceedings instituted to challenge the validity of any steps taken in pursuance of the construction of the segment of the interstate system between south Bellevue and state route No. 5 in Seattle, or the construction of substitute public mass transit projects in lieu thereof, shall take precedence over all other causes not involving the public interest in all courts of this state to the end construction of such facilities may be expedited to the fullest. The legislature of the state of Washington respectfully requests of the federal judiciary that challenges instituted in the federal courts relating to the validity of steps leading to the construction of the designated interstate highway or substitute public mass transit projects in lieu thereof be expedited to the fullest.