The airport capacity problem has recently received a great deal of attention due to airport congestion and delays. Capacity improvements of airfield and airspace component of an airport are currently being addressed by several researchers and federal and state agencies. The optimal location of runway turnoffs is the focus of this research. Although the current airport capacity limitations are dictated by airspace separation rules, it is expected that runway occupancy time (ROT) will become an important factor In the near future as the interarrival separations between landing aircraft are reduced. The intent of this research is to show that the use of high speed exits on runway contributes to the reduction of ROT, and therefore provides enhancement in runway capacity. However, locating the high speed exits is a complex and dynamic problem stemming from the aircraft landing behavior. The landing behavior of an aircraft is affected by many factors such as approach speed, deceleration rate, design exit speed, airport elevation, wind, temperature, etc .. Some of these factors are probabilistic in nature. A simulation model and an optimization algorithm that take into consideration all above factors developed to address the problem. The simulation model consists of a series of dynamic equations of motion that models the aircraft landing behavior under various airport conditions, and determines the best exit location for that aircraft. The optimization model takes the simulation results as input for various aircraft mix, and finds a given number of exit locations which minimize the average ROT for the total aircraft fleet. / Master of Science