1. All web-based references were last accessed in March 2011
2. Broaddus A, Litman T, Menon G (2009) Training document on transportation demand management. Sustainable Urban Transport Project ( http://www.sutp.org ) and GTZ ( http://www.gtz.de )
3. Cairns S et al (2004) Smarter choices – changing the way we travel. UK Department for Transport ( http://www.dft.gov.uk )
4. Cambridge Systematics (2009) Moving cooler: transportation strategies to reduce greenhouse gas emissions ( http://www.movingcooler.info ). Co-sponsored by a variety of organizations; report at http://commerce.uli.org/misc/movingcooler.pdf ; summary at http://commerce.uli.org/misc/movingcoolerexecsum.pdf
5. Clarke H, Prentice D (2009) A conceptual framework for the reform of taxes related to roads and transport. School of Economics and Finance, La Trobe University, for the Australia Treasury Australia’s Future Tax System review. http://apo.org.au/research/conceptual-framework-reform-taxes-related-roads-and-transport