Evaluation of S.R. 46 wildlife crossing in Lake County, Florida

  • Published source details Roof J. & Wooding J. (1996) Evaluation of S.R. 46 wildlife crossing in Lake County, Florida. Florida Game and Fresh Water Fish Commission report.


This study is summarised as evidence for the following.

Action Category

Install barriers and crossing structures along roads/railways

Action Link
Reptile Conservation

Install barrier fencing and underpasses along roads

Action Link
Terrestrial Mammal Conservation
  1. Install barriers and crossing structures along roads/railways

    A before-and-after study in 1993–1995 in forest and pasture in Florida, USA (Roof & Wooding 1996) found that after a fence and wildlife underpass was built, numbers of road-killed reptiles did not decrease, but tortoises and snakes used the crossing. Sample sizes were small and results were not statistically tested. In the year after a fenced wildlife underpass was installed, two box turtles Emydidae spp., one cooter Pseudemys concinna and one gopher tortoise Gopherus polyphemus were killed on the road, compared to one box turtle before installation. The underpass was used by two gopher tortoises and 12 snakes (species not identified). One alligator mississippiensis walked along the fence line but did not use the crossing. A wildlife underpass (14.3 m long, 7.3 m wide, 2.4 m high) and barrier fencing (3 m chain-link and barbed wire fence topped with three strands of barbed wire, both sides of the underpass, 1.7 km total length) was erected in 1994. Trails were cut into woodland and trees planted in pasture to guide wildlife to the underpass. Roadkill surveys were carried out three times/week pre-fencing (December 1993–November 1994) and post-fencing (December 1994–November 1995). In December 1994–December 1995, movements along the fence line and in the underpass were monitored by surveying tracks and a camera in the centre of the underpass.

    (Summarised by: Katie Sainsbury)

  2. Install barrier fencing and underpasses along roads

    A before-and-after study in 1993–1995 of a highway in Florida, USA (Roof & Wooding 1996) found that an underpass beneath a highway, in an area with roadside fencing, was used by mammals but the road-kill rate was not reduced. Nine mammal species used the crossing. Most crossings were by rabbits Sylvilagus palustris (69 crossings), racoons Procyon lotor (61), armadillos Dasypus novemcinctus (36), opossums Didelphis virginiana (36), foxes Vulpes vulpes (29) and bobcats Lynx rufus (27). The number of mammals of squirrel size or larger killed on the fenced road section was not significantly different in the 11 months after fence installation (13 animals) relative to the 11 month before (10 animals). A wildlife crossing (14.3 m long, 7.3 m wide and 2.4 m tall) was constructed under the two-lane highway between summer and December 1994. A 3-m-high fence extended along both sides of the highway, 0.6 km in one direction and 1.1 km in the other. Underpass use was determined in December 1994 to December 1995 by footprint surveys and by using a motion-triggered camera. Road-kills were surveyed three times/week from November 1993 to December 1995.

    (Summarised by: Nick Littlewood)

Output references
What Works 2021 cover

What Works in Conservation

What Works in Conservation provides expert assessments of the effectiveness of actions, based on summarised evidence, in synopses. Subjects covered so far include amphibians, birds, mammals, forests, peatland and control of freshwater invasive species. More are in progress.

More about What Works in Conservation

Download free PDF or purchase
The Conservation Evidence Journal

The Conservation Evidence Journal

An online, free to publish in, open-access journal publishing results from research and projects that test the effectiveness of conservation actions.

Read the latest volume: Volume 21

Go to the CE Journal

Discover more on our blog

Our blog contains the latest news and updates from the Conservation Evidence team, the Conservation Evidence Journal, and our global partners in evidence-based conservation.

Who uses Conservation Evidence?

Meet some of the evidence champions

Endangered Landscape ProgrammeRed List Champion - Arc Kent Wildlife Trust The Rufford Foundation Save the Frogs - Ghana Mauritian Wildlife Supporting Conservation Leaders
Sustainability Dashboard National Biodiversity Network Frog Life The international journey of Conservation - Oryx Cool Farm Alliance UNEP AWFA Bat Conservation InternationalPeople trust for endangered species Vincet Wildlife Trust