Key points are not available for this paper at this time.
Eigenbrod, F., S. J. Hecnar, and L. Fahrig. 2009. Quantifying the road-effect zone: threshold effects of a motorway on anuran populations in Ontario, Canada. Ecology and Society 14(1): 24. https://doi.org/10.5751/ES-02691-140124
Eigenbrod et al. (Thu,) studied this question.