Two routes connect an origin and a destination and the total trips between them is 15,000 veh/hr. Route 1 has a free flow travel time of 4 mintutes and travel time increases by 3 minutes and for each additonal 1000 vehicle in flow, and route 2 has a free flow travel time of "b" minutes and travel time increases by 3 minutes for each additional 500 vehicle in flow. If the user equilibrium flow on route 1 is 9,780 veh/hr, determine: Free-flow travel time on route 2 (i.e. "b") and Equilibrium travel times.