This paper investigates pedestrian exposure to traffic emissions at the Marylebone Road–Gloucester Place intersection in central London, taking a particular interest in the peak exposures occurring within minutes. The approach is based on the large eddy simulation modelling methodology, which enables high spatial resolution of air movements and pollutant concentrations to be achieved at relatively moderate computational cost. The results show the complexity of the air flows in the vicinity of the intersection at pedestrian height and the large variability of peak exposures due to the turbulent air flows.