Dear David, Hope that you are focusing your attention to the impact of vehicles on extinctions of amphibians. Even though common toads and fire salamanders are not found in our area, road kills is a one of the major reasons for declining of amphibians in our region too. Sometimes, following links may useful for you.

Article Spatial distribution and seasonal pattern in road mortality ...

Article Amphibian and reptile road-kills on tertiary roads in relati...

Article Amphibian road mortality in Europe: A meta-analysis with new...

https://link.springer.com/content/pdf/10.1007/s10344-012-0618-2.pdf

https://www.thebhs.org/publications/the-herpetological-bulletin/issue-number-121-autumn-2012/4-2-decline-and-flounder-of-a-sussex-common-toad-i-bufo-bufo-i-population/file

Beebee TJ. 2013. Effects of road mortality and mitigation measures on amphibian populations. Conservation Biology 27(4): 657-68. doi: 10.1111/cobi.12063.

Abstract

Road mortality is a widely recognized but rarely quantified threat to the viability of amphibian populations. The global extent of the problem is substantial and factors affecting the number of animals killed on highways include life-history traits and landscape features. Secondary effects include genetic isolation due to roads acting as barriers to migration. Long-term effects of roads on population dynamics are often severe and mitigation methods include volunteer rescues and under-road tunnels. Despite the development of methods that reduce road kill in specific locations, especially under-road tunnels and culverts, there is scant evidence that such measures will protect populations over the long term. There also seems little likelihood that funding will be forthcoming to ameliorate the problem at the scale necessary to prevent further population declines.

Dear David,

Please check the following ResearchGate link and PDF attachments.

https://www.researchgate.net/publication/281755635_Amphibian_Road_Mortality_and_How_to_Prevent_It_A_Review

Good luck!