Advanced traveler information systems (ATIS) attempt to provide drivers with data intended to help them make better travel decisions. Messages may be available to all drivers (for example by radio or television broadcasts) or only to some: for example, those who pass near a particular infrastructure (such as variable message signs or VMS) or who have special receivers in their vehicles. Drivers, of course, may react to the messages in any way they choose.

Traditional travel surveys provide essential information on travel patterns, but are time-consuming, expensive, and have seen declining rates of participation. Recently global positioning systems (GPS) technologies have been introduced to facilitate the data collection process. While GPS traces can provide accurate information on the location and time of travel, these traces do not contain explicit information on the mode used (e.g., walking, biking, transit or auto).

Traditional travel surveys provide essential information on travel patterns, but are time-consuming, expensive, and have seen declining rates of participation. Recently global positioning systems (GPS) technologies have been introduced to facilitate the data collection process. While GPS traces can provide accurate information on the location and time of travel, these traces do not contain explicit information on the mode used (e.g., walking, biking, transit or auto).

Finding an effective method for obtaining information on the travel patterns of household members is a critical need for transportation planners and researchers. This is particularly the case for Metropolitan Planning Organizations (MPOs), now being pressured to improve their travel demand forecasting capabilities. An emerging strategy for generating high-quality data is the use of Global Positioning Systems (GPS) trace data to collect travel patterns.