[1] Kantonen, J. and K. Toivonen. "Road weather and road conditions services for motorists," Finnish National Road Administration, 1996.
[2] G Van den Hoogen, E. and S. Smulders, “Control by variable speed signs: results of the Dutch experiment,” Seventh International Conference on Road Traffic Monitoring and Control, London, April 26-28, 1994.
ieeexplore.ieee.org/iel3/3097/8739/00385798.pdf?
[3] Y. Pilli-Sihviala and L. Jukka, "Weather controlled road and investment calculations," Finnish National Road Administration, 1995.
http://www.itslessons.its.dot.gov/its/benecost.nsf
[4] J. Placer, A. Sagahyroon, and J. Harper “Design of a fuzzy variable speed limit system for rural highways,” Rural Advanced Technology and Transportation Systems 1998 International Conference, August 31-September 1998.
www.azdot.gov/TPD/ATRC/publications/research_notes/PDF/466(2)RN.pdf
[5] J. Placer, A. Sagahyroon, and J. Harper, “Creating an intelligent variable speed limit system for rural highways,” International Symposium on Automotive Technology and Automation, 32nd, 14th-18th June 1999.
[6] A.T. Ibrahim and F.L. Hall. "Effect of adverse weather conditions on speed," Transportation Research Record 1457, Transportation, (1994).
http://pubsindex.trb.org/document/view/default.asp?lbid=425358
[7] W. Brilon and M. Ponzlet. "Variability of speed-flow relationships on German" Autobahns, Transportation Research Record 1555, Transportation Research Board, Washington, D.C. (1996).
[8] W.L. Liang , M. Kyte, F. Kitchener, and P. Shannon "Effect of environmental factors on driver speed", Transportation Research Record 1635, Transportation Research, (1998).
http://trb.metapress.com/content/7671405341710043/
[9] P. L. Olson, D. E. Cleveland, P. S. Fancher, L. P. Kostyniuk, and L. W. Schneider, "Parameters affecting stopping sight distance," NCHRP Report 270, Transportation Research Board, 1984.
[10] L. Senn, "Variable speed limit and in-vehicle signing operational test," Washington State Department of Transportation, 1997.
[11] M. Kyte, Z. Khatib, P. Shannon, and F. Kitchener, "Effect of environmental factors on free-flow speed," Fourth International Symposium on Highway Capacity, ISSN: 0097-8515, June 26, 2000.
http://pubsindex.trb.org/document/view/default.asp?lbid=657336
[12] S. Haykin "Neural networks, a comprehensive foundation," International Edition, Second Edition. Prentice Hall International, Inc, USA, 1999.