A method of reducing congestion is to reduce the demand by providing the road network users with accurate and reliable travel time information for their pretrip planning and enroute guidance, and/or attracting more people to the public transit. For this purpose, this research concenturates on using Automatic Vehicle Location (AVL) system equipped bus as a probe vehicle for estimating bus arrival times and auto travel times. Since many transit organizations throughout the North America are currently operating these AVL buses on their bus routes, in a sense, existing AVL bus would be the most cost-effective traffic probe which can be utilized for data collection in the proactive mode. Therefore, the goals of this research are to enhance the current use of AVL systems by introducing a new module to estimate bus arrival time information for transit travelers, and use AVL systems-equipped bus as a probe vehicle to estimate the nontransit travel time for auto travelers. / Ph. D.