A freeway with two northbound lanes is shut down because of an accident. At the time of the accident, the traffic speed is 40mph, and the flow rate is 1200 vehicles per hour per lane. The arriving traffic flow rate and speed will remain at this level. The capacity of the freeway is 2400 vehicles per hour per lane with a speed 60mph when not impacted by an accident. The freeway jam density is 180 vehicles per mile per lane. The freeway is shut down completely for 40 minutes and finally both lanes are opened. Using the shockwave theory, determine when the queue will be cleared completely and at the time of clearance, how far upstream the traffic has been impacted by the accident