S. C. Tignor, et al., “Innovative Traffic Control Technology and Practice in Europe,” 1999.
 Indiana Department of Transportation Press Release, “Clark County I-65 Exit 4 Solution Proves Successful,” 2000.
 King County Department of Transportation Press Release, “New Traffic Warning System Improves Safety Near Elementary School,” 2002.
 P. B.Wiles, S. A. Cooner, C. H. Walters and E. J. Pultorak, “Advance Warning of Stopped Traffic on Freeways: Current Practices and Field Studies of Queue Propagation Speeds,” FHWA/TX-03/4413-1, 2002.
 FOCUS, Federal Highway Administration, “Queue Length Detector Reduces Risk of Rear-End Accidents in Work Zones,” 1998.
 P. D. Pant, “Implementation and Testing of the Travel Time Prediction System (TIPS),” Final Report Prepared in Cooperation with the Ohio Department of Transportation and The US Department of Transportation, Federal Highway Administration, 2001.
 K. K. Dixon, “Evaluating Speed Reduction Strategies for Highway Work Zones (Smart Work Zones),” Final Report, Prepared for Georgia Department of Transportation Prepared by Georgia Transportation Institute Georgia Institute of Technology, 2005.
 A. J. Horowitz and T. Notbohm, “Evaluation of Intellizone: A System for Providing Speed Advisories to Drivers Entering Work Zones,” Report to Widwest Smart Work Zone Initiative, FHWA Pool Fund Study, 2003.
 K. C. Sinha and S. Labi, “Transportation Decision Making: Principles of Project Evaluation and Programming,” John Wiley & Sons Inc., Hoboken, 2007.