[1]       "A policy on geometric design of highways and streets" Chapter 3 Design elements, 2004, AASHTO

[2]       Mannering F.L., Kilareski W.P., and Washburn S. S, "Principles of Highway Engineering and Traffic Analysis ", 3rd edition, John Wiley & Sons, Inc. 2005

[3]       Ames A.L., Nadeau D.R., and Moreland J.L., "VRML 2.0 Source Book ", 2nd edition, John Wiley & Sons, Inc. 1997

[4]       Online users manual of roadway geometry design software ( PDF).

[5]       CE3201 "Introduction to Transportation Engineering" class notes, Department of Civil Engineering, University of Minnesota,