1. ABW (Alliance for Biking & Walking) (2014): Bicycling and Walking in the United States: 2014 Benchmarking Report. https://www.bikewalkalliance.org/storage/documents/reports/2014BenchmarkingReport.pdf
2. ACS (American Community Survey) (2015): B08301 Means of Transportation to Work, 2013 ACS 1-Year-Estimates. United States Census Bureau.
3. Amtrak (2012): For 21 years Amtrak has provided a high return on limited federal investment, says boardman. http://www.amtrak.com/ccurl/918/952/Amtrak-Provided-High-Return-on-Federal-Investment-ATK-12-082.pdf , abgerufen am 3. März 2014
4. Amtrak (2013): National Fact Sheet: FY 2012. Retrieved February 1, 2014. from http://www.amtrak.com/ccurl/355/968/Amtrak-National-Fact-Sheet-FY2012.pdf
5. Amtrak (2014): National Fact Sheet: FY 2013. http://www.amtrak.com/ccurl/228/846/Amtrak-National-Fact-Sheet-FY2013.pdf , abgerufen am 3. März 2014