A mode-of-station-access survey at the Milwaukee District North Line Grayland and Mayfair Stations in Chicago is described. The study was conducted to determine the impacts of consolidating these two stations into a single new station. Patterns of different station access modes were studied. The analysis focused on the most sensitive market segment-walkers. Two different methods were used to determine how current walkers would be affected by such a station change. The first estimate was based on changes in walking distances. A heuristic procedure was developed to estimate the number of walkers currently using the system who would possibly walk to the proposed new station. This estimate assumed that stations would attract walkers from a circular area referred to as the catchment area. The average walking distance to each station determined its catchment area size. Further assumptions were made to predict those walkers who were not currently in the catchment areas but who would decide to walk to the new station. This study provides intuitive results and methodology that show promise for use in similar situations.