Abstract
Travel time reliability has become an important factor in route choice analysis and is one of the key indicators for traffic performance measurement. Hence this study assessed the ten corridors of the Adelaide Metropolitan road network's travel time reliability by using the Buffer Time and Planning indices. The findings show that the Buffer Time indices for the selected corridors may significantly vary and for some corridors, they reach almost 100 per cent. Since the buffer time index seems to overestimate the travel time reliability measurement, a detailed assessment of the travel time distribution was also conducted. This analysis shows that none of the travel time distributions follow the normal distribution. However for some corridors the log normal distribution would fit the travel time distribution
