Consider a three-lane homogeneous freeway section. The processing of data from video recordings shows that the traffic behavior is identical among the freeway travel lanes. The jam spacing is 30 ft/veh, the average free flow speed is 55 mph and the minimum vehicle headway is 1.8 sec/veh. One particular day when traffic was free flowing at a rate of 1,800 vph/lane, an accident occurred on the opposite side of the freeway andcaused the density to increase at the test section to 100 veh/mile/lane due to rubbernecking. After 15 minutes the accident was removed, and traffic began to recover to normal operations. (a) Draw the fundamental diagram for this section of highway assuming that it is triangular, and identify and label the relevant trac states.
(b) Draw a time-space diagram showing the shockwaves and sketching some vehicle trajectories. Label the trac states on the time-space diagram corresponding to the states you identied in part (a). Calculate and label the speeds of shockwaves.
(c) How long does it take for the entire section of road to resume normal trac conditions?
(d) What is the maximum extent (i. e., physical length) of the queue from the incident?
(e) How many vehicle miles and vehicle hours are traveled in the queue?