1. American Association of State Highway and Transportation Officials (AASHTO) (2006) Roadside design guide, 3rd edn. AASHTO, Washington, DC
2. American Association of State Highway and Transportation Officials (AASHTO) (2011) Roadside design guide, 4th edn. AASHTO, Washington, DC
3. Armstrong JJ (1994) Dead animal observations on Ontario highways. Ontario Ministry of Transportation. Appended in Hubbs A, Boonstra R (1995) Study design to assess the effect of highway median barriers on wildlife. Ontario Ministry of Transportation
4. Bank FG, Irwin C, Evink G, Gray M, Hagood S, Kinar J, Levy A, Paulson D, Ruediger B, Sauvajot R, Scott D, White P (2002) Wildlife habitat connectivity across European highways. Office of International Programs, Publication No. FHWA-PL-02-011. Federal Highway Administration, Washington, DC
5. Barnum SA (2003) Identifying the best locations along highways to provide safe crossing opportunities for wildlife: a handbook for highway planners and designers. Report No. CDOT-DTD-UCD-2003-9 Final Report. Colorado Department of Transportation, Denver