Question

A rural highway has capacity of 5.000 veh/h. One morning, traffic flows at constant rate of 3.000 veh h when. suddenly. at 8:00am. a major accident takes place. and the highway is totally hour blocked for 20 minutes. Then it starts to operate at reduced capacity of 2.000 yeh/hr for one which improves to 3,000 yely h during the next hour, and finally at 10:20am the full capacity is restored a) What is the maximum length b) What time does the flow retur eue, and at what time? urmal (no more queue of vehicles)

Answer 1

maximum queue length = Delay times flow rate Delay is between 8: 00 Am to 8: 20 AM . So delay is 20 minutes which is 20/60 hours Therefore maximum queue length = 20/60 times 3000 = 1000 vehicles b) The capacity was 2000 veh/hr from 8: 20 AM for 1 hour. Later it was 3000 veh/hr for 1 hour So , t he how returned to original after 1 hour from 8: 20 AM so the time t which the flow returned to normal was 9: 20 AM