Peter Stopher is Professor of Transport Planning at the Institute of Transport and Logistics Studies at the University of Sydney. He has also been a professor at Northwestern University, Cornell University, McMaster University and Louisiana State University. Professor Stopher has developed a substantial reputation in the field of data collection, particularly for the support of travel forecasting and analysis. He pioneered the development of travel and activity diaries as a data-collection mechanism, and has written extensively on issues of sample design, data expansion, nonresponse biases and measurement issues.