http://www.iii.org/fact-statistic/auto-insurance
Number One Issue for the Public: Price of Travel – http://www.fhwa.dot.gov/policy/2013cpr/chap1.htm#5
National Travel Trends (see Table 17) http://nhts.ornl.gov/2009/pub/stt.pdf
Joseph Ferreira Jr. and Eric Minike (2010), Pay-As-You-Drive Auto Insurance In Massachusetts: A Risk Assessment And Report On Consumer, Industry And Environmental Benefits, by the Department of Urban Studies and Planning, Massachusetts Institute of Technology (http://dusp.mit.edu) for the Conservation Law Foundation (www.clf.org); at http://www.clf.org/wp-content/uploads/2010/12/CLF-PAYD-Study_November-2010.pdf.
Litman, Todd. 2008 (a). “Distance‐based vehicle insurance feasibility, costs and benefits.” Victoria Transport Policy Institute. http://www.vtpi.org/dbvi_com.pdf
Litman, Todd. 2008 (b). “Pay‐As‐You‐Drive insurance: recommendations for implementation.” Victoria Transport Policy Institute. http://www.vtpi.org/payd_rec.pdf
Greenberg, Allen. 2009. “Costs and benefits of varying per‐mile insurance premiums based upon measured risks specific to each mile driven.” Federal Highway Administration, http://www.vtpi.org/AG_PAYD.pdf
Transportation Energy Data Book Chapter 8 Household Vehicles and Characteristics
http://www-cta.ornl.gov/data/chapter8.shtml see Table 8-5