An enhanced version of kronos, a dynamic, microcomputer-based freeway simulation program, is presented. Kronos is based on mesoscopic continuum modeling and explicitly treats the coupling effects of ramps on the freeway flow in detail. The major improvements of the new version include the substantial reduction of computer execution time and the addition of new simulation modules that can describe the flow behavior under restricted capacity situations, such as incidents and short-term construction. Further, a newly developed output interface links kronos with other advanced data management and analysissoftware, so that more detailed and flexible output analysis can bepossible. In order to test and validate the program in real trafficenvironments, field data collection was performed at 26 locations covering an 8-mi section of the i-35w freeway in minneapolis, minnesota. The data consist of 5-min volume and speed information for each lane during three morning and three afternoon peak periods. The testresults with the available data indicate satisfactory performance of the enhanced kronos program in light-to-moderate traffic conditions, although the error increased during heavy congestion. This paper appears in transportation research record no. 1320, Freeway operations, highway capacity, and traffic flow 1991.
Abstract