Providing evidence to improve practice

Individual study: A literature review of the effects of roads on amphibians and reptiles and the measures used to minimize those effects

Published source details

Jochimsen D.M., Peterson C.R., Andrews K.M. & WhitfieldGibbons J. (2004) A literature review of the effects of roads on amphibians and reptiles and the measures used to minimize those effects. Idaho Fish and Game Department and USDA Forest Service report.


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Install barrier fencing along roads Amphibian Conservation

A study of drainage culverts modified with diversion fencing in Texas, USA (Jochimsen et al. 2004) found that fencing reduced road-kills in its vicinity, but aggregations of dead toads were recorded at the barrier endpoints. No Houston toads Bufo houstonensis used the culverts, which became impassable when flooded. Short sections of steel diversion fencing were added to existing drainage culverts to guide toads from known migration routes into the culverts.

Install culverts or tunnels as road crossings Amphibian Conservation

A review of studies investigating culverts in Texas and near New York, USA (Jochimsen et al. 2004) found mixed results. Two tunnels with barrier walls decreased amphibian road deaths by 90%. Eight of the 20 known species were recorded using the tunnels. In contrast, no Houston toads Bufo houstonensis used modified drainage culverts and athough diversion fencing reduced road-kills in its vicinity, groups of dead toads were recorded at the ends. Short sections of steel diversion fencing were added to existing drainage culverts to guide toads from known migration routes into the culverts. The culverts were not designed for amphibians and became impassable when flooded. Two concrete tunnels with box openings (1.2 x 1.2 m) and wooden barrier walls were installed along a road adjacent to wetlands in 1999.