Organisation Guideline Reptiles & Amphibians Lizards Snakes Tortoises Turtles (freshwater) Salamanders & Newts Toads Frogs
English Nature (now Natural England) Great crested newt mitigation guidelines - - - - - 50cm - -
USFWS Desert Tortoise Fencing Specifications - - - 55cm - 60cm (22 inches - 24 inches) - - - -
Amphibian and Reptile Conservation Common Toads and Roads: Guidance for planner and highways engineers (England) - - - - - - 40 cm (16 inches). -
Queensland Department of Transport and Main Roads Fauna Sensitive Road Design Manual Volume 2: Preferred Practices (2010) 40 cm - 60 cm (16 inches - 24 inches). - - - 40 cm (16 inches). - - 40 cm (16 inches).
Vic Roads Fauna sensitive road design guidelines 40 cm - 60 cm (16 inches - 24 inches). - - - - - - 40 cm (16 inches).
Western Transport Institute, Montana State University Construction guidelines for wildlife fencing and associated escape and lateral access control measures - 60cm - 110 cm (24 inches to - 43 inches). 60cm - 110 cm (24 inches to - 43 inches). 30 cm - 60 cm (12 inches - 24 inches). 30 cm - 60 cm (12 inches - 24 inches). 40 cm - 60 cm (16 inches - 24 inches). 40 cm - 60 cm (16 inches - 24 inches). 40 cm - 60 cm (16 inches - 24 inches).
Ministry of Agriculture, Food and the Environment Technical prescriptions for wildlife crossing and fence design (second edition, revised and expanded) - - - 40 cm (16 inches). - - - -
Ontario Ministry of Natural Resources and Forestry. Best Management Practices for Mitigating the Effects of Roads on Amphibians and Reptile Species at Risk in Ontario. - 50 cm (20 inches). 60 cm- 200 cm (24 inches - 79 inches). - 60 cm (24 inches). 30 cm (12 inches). 50 cm (20 inches). -
Wildlife Institute of India Eco-friendly measures to mitigate impacts of linear infrastructure on wildlife > 80 cm (> 31 inches) - - - - - - -
Ministry of Environment and Climate Change Strategy Guidelines for Amphibian and Reptile Conservation During Road Building and Management Activities in British Columbia - - 100 cm (40 inches). - 60 cm - (24 inches). 30 cm (12 inches). 50 cm (20 inches). 50 cm (20 inches).
Caltrans Measures to Reduce Road Impacts on Amphibians and Reptiles in California:Best Management Practices and Technical Guidance - 33 cm - 76 cm (13 inches -30 inches). 64 cm - 110 mcm (25 inches - 43 inches). 46 cm (18 inches). 38 cm - 91 cm (15 inches - 35 inches). 38 cm (15 inches). 46 cm - 64 cm (18 inches - 25 inches). 76 cm - 97 cm (30 inches - 38 inches).
IENE Wildlife and Traffic: A European Handbook for Identifying Conflicts and Designing Solutions 40 cm -60 cm (16 inches - 24 inches). - - - - - - -
Arizona Fish & GameĀ  Department Wildlife Compatible Fencing - - 122 cm (48 inches). 15 cm (6 inches). - - - -