Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!linus!wivax!decvax!harpo!seismo!hao!hplabs!sri-unix!RHB@MIT-MC From: RHB%MIT-MC@sri-unix.UUCP Newsgroups: net.physics Subject: physical laws of freeway traffic? Message-ID: <2172@sri-arpa.UUCP> Date: Wed, 15-Jun-83 11:56:00 EDT Article-I.D.: sri-arpa.2172 Posted: Wed Jun 15 11:56:00 1983 Date-Received: Sat, 18-Jun-83 04:57:50 EDT Lines: 23 From: Robert H. BermanA good review of the models of traffic may be found in "Traffic Science" edited by D.C. Gazis, 1974 (John Wiley). The first chapter deals with flow theories of traffic and introduces the hydrodynamic model of traffic flow (shock wave propagation, acceleration waves, lights, speed flows, density, etc) in both high density and low density traffic regimes on highways. It also talks about simple statistical models. More sophisticated porbabilistic descriptions of the gaps in traffic are discussed in other chapters. There is a rather interesting dsicussion of the control problems in synchronizing traffic lights. Basically, in terms of the original question about stop-and-go traffic, the hydrodynamic model would predict the occurance of acceleration and deceleration density waves that the driver is experiencing. The difficulty in driving is related as to where the driver is and his motion relative to the shock front associated with these waves. A driver should try to move so that any shock front is stationary (in his frame) and that the average relative velocity between him and his neighbors is minimized. In other words, "go with the flow", not with the speed limit.