The objective of the NGSIM program is to develop a core of open behavioral algorithms in support of traffic simulation, with a primary focus on microscopic modeling, including supporting documentation and validation data sets that describe the interactions of multi-modal travelers, vehicles and highway systems, and interactions presented to them from traffic control devices, delineation, congestion and other features of the environment.
More information can be found on the NGSIM website: http://ngsim.camsys.com