Two decades later, researchers at TFHRC, with assistance and participation from universities and private industry, merged NETSIM
and FRESIM into a single microscopic model, CORSIM, and developed the Traffic Software Integrated System (TSIS) package, which is a collection of software tools for use by traffic engineers and researchers.
The Federal Highway Administration (FHWA) is a leader in developing traffic microsimulation models, dating back to the development of NETwork SIMulation (NETSIM
) in the 1970s, FREeway SIMulation (FRESIM) in the 1980s, and the merging of NETSIM
and FRESIM into a single CORridor SIMulation (CORSIM) model, all of which was integrated into the Traffic Software Integrated System (TSIS) package in the 1990s.