This document summarizes research on assessing mode shift behavior due to the introduction of new mass transit systems. It discusses various survey methods used to collect data on commuter demographics, travel characteristics, and current versus hypothetical travel behavior. Models are developed to analyze survey data and compare scenarios with and without new transit modes. The probability of mode choice and shifts from private vehicles or existing transit to new systems like metro or bus rapid transit are examined. Methodologies to evaluate these mode choice probabilities using stated preference and revealed preference surveys are also outlined.