1. Appendix I: Climate Zone Definitions;Federal Highway Administration,2000
2. J. Mahoney, M. Rutherford, R. Hicks, Guidelines for Spring Highway Use Restrictions, 1987.
3. Federal Highway Administration, Highway Performance Monitoring System Field Manual, 2014.
4. National Climatic Data Center. Air Freezing Index-USA Method, National Climatic Data Center [cited 2017 April 1st]; Available from: https://www.ncdc.noaa.gov/sites/default/files/attachments/Air-Freezing-Index-Return-Periods-and-Associated-Probabilities.pdf.
5. Calculating insulation needs to fight frost heave by comparing freezing index and frost depth. In: Tech Solutions 605.0. DOW Chemical Canada-Building Solutions. Available from: http://msdssearch.dow.com/PublishedLiteratureDOWCOM/dh_01f6/0901b803801f6296.pdf?filepath=styrofoam/pdfs/noreg/178-00754.pdf&fromPage=GetDoc.