Question

the traffic during office hours increases by 20% in the morning . During the daytime,it fall 20% . what is the net rise or fall in traffic?

Answer 1

There is some fine tuning required in analysis of your question.

Consider this (assuming 8:00 am to 9:00 am as peak hour on some road)



Total vehicles in 15 min between 8:00 to 8:15 am is 100. Thus at this rate, total flow of vehicles in 1 hour will be 100 x 4 = 400 (because, 1 hour = 4 x 15 min). similarly other data in table. Interesting thing to observe is, even though total vehicles passing in 1 hour is 550, flow rate (last column) is varying every 15 min. Depending upon capacity of road, congestion is most likely to occur between 8:46 - 9:00 am. This is how net rise or fall in traffic is calculated.

Hope this helps.