Sen received his school certificate in 1958 from St. Xavier's College in Calcutta, India. He received his B.S. in mathematics in 1962 with honors from Calcutta University, his M.A. in mathematics and his Ph.D. in statistics from the University of Toronto in 1964 and 1971 respectively. The President of United States nominated Ashish Sen to serve as Director of the Bureau of Transportation Statistics at the Department of Transportation (DOT) of USA. Prior to that he served as Director of the Statistics and Evaluation Laboratory at the Urban  Transportation Center at the University of Illinois in Chicago since 1996 and in 1997 he was also named the Director of the Urban Transportation Center. From 1978 until the present he has been a Professor of Urban Planning and since 1995 he has also served as a Professor of Mathematics, Statistics, and Computer Science at the University of Illinois at Chicago. From 1969 to 1978, he served in various capacities within the College of Urban Sciences at the University of Illinois at Chicago Circle including Associate Professor, Acting Dean, and Director of the School of Urban Sciences. He has authored numerous articles and co-authored two books relating to statistics and transportation.