1. One possible approach that seems to be reliable is explained in: “Methodology for assessing dynamics of freeway traffic flow,(M. Cassidy and J. Windover), Trans. Res. Rec. 1484, 73–79, 1995”.
2. See “Incident detection with data from loop surveillance systems: The role of wave analysis. (W.H. Lin) PhD thesis, Dept of Civil and Environmental Engineering, University of California, Berkeley, 1995.” This reference also discusses the state of the art in incident detection.
3. Some interesting figures can be found in “Some traffic features at freeway bottlenecks. (M. Cassidy and R. Bertini) Institute of Transportation Studies Research Report ITS-RR-97–07, U. of California, Berkeley, CA, 1997; Trans. Res. A. (in press),” and also in not yet published work by M. Mauch.
4. A detailed explanation of the theory can be found in Sec. 2 of “The nature of freeway gridlock and how to prevent it,(C. Daganzo) in Transportation and Traffic Theory,pp. 629–646, J.B. Lesort, editor, Pergamon-Elsevier, New York, N.Y., 1996.” This reference also describes the implications of the theory for ramp metering.
5. A detailed explanation of the theory, including its discretization for computer calculation, can be found in Secs. 3.3 and 4 of “The cell transmission model part II: network traffic. (C. Daganzo) Trans. Res. 29B, 79–93, 1995”.