[vijaymv_in]

Here is how I would have approached. The average commute time is 40 mins for New Yorker. The population is 12 millions and during a work day it goes up to 20 million.

So I assumer 20 Ml . Out of the 40 mins assume 20 mins spend on 15 mins- 20 mins spend on path, LIRR, NJ Transit etc.. so this gives around 20 - 25 mins of average commute in subway.

Assuming arounds 40 percentage uses subway

8 million * 5 - 7 miles= 40 - 50 million miles..