縦断勾配
↑ Highway code: Warning signs
↑ “The New Pöstlingberg Railway” (PDF). Linz Linien GmbH (2009年). 2011年1月6日閲覧。
↑ http://whc.unesco.org/en/tentativelists/2082/
↑ C.Michael Hogan, Analysis of highway noise, Journal of Water, Air, & Soil Pollution, Volume 2, Number 3, Biomedical and Life Sciences and Earth and Environmental Science Issue, Pages 387-392, September, 1973, Springer Verlag, Netherlands ISSN 0049-6979