Wildlife FAQ - ACO SWM
United States



ACO Wildlife tunnels are intended for providing safe passage across roads to small animals, primarily amphibians. Its intended use is for locations where these small animals pass the road in large numbers at given times which, without any measures, translate to very high numbers of road mortality threatening the species survival.

Yes there are numerous installation in USA, Canada and Europe. This product first became available in the 1980’s.

Clear width is 20” (0.5m) and clear height is 12” (0.3m).

ACO tunnels are one of the most cost effective mitigation measures for amphibian road mortality hot spots. Pipe can also be used, however, studies shown that pipe needs to be at least 1m diameter to be as effective as the ACO tunnel. This is due to the fact that, although ACO tunnel is smaller, it has top openings that allow moisture, light and regulate temperature inside the tunnel creating an environment closer to the exterior. Moreover, the ACO tunnel is much shallower than any pipe installation. In some instances pipe simply cannot be used as it would create a low point and get filled with water.

Polymer concrete. This material is 4 times as strong as cement concrete, does not release any VOC or other chemicals in the surrounding soil and it is insensitive to salt, extreme low temperatures or freeze-thaw cycles. Because is non-metallic it does not interfere with the magnetic orientation of some animals. Furthermore, amphibians’ skin will not dry out when they crawl on polymer concrete ensuring safe passage through it.

The tunnel is designed for frequent passes of heavy duty vehicles – H25 per AASHTO M306 or load class D per EN1433.

When installed correctly, polymer concrete tunnels perform very well in snow plow active areas. Although the top will chip in contact with snow plow blades, it will take many years for this to create a structural issue. There installations in Massachusetts, Quebec and Ontario between 10 and 33 years that are still in use.

Common species where studies show it provides good performance in utilization by targeted species are toads, salamanders, small snakes (non-climbing), turtles, etc. Visit the Scientific Studies on our website to learn more about various species.

The tunnels will not work without using a fence guiding system. It is this fence that will not permit road passage in any point other than the tunnel location.

Fence units are made of polyethylene, a material that has a good strength and longevity in outdoor environments.

The ACO guiding fence is meant for use in conjunction with the tunnels. It targets small species that cannot jump, climb or otherwise pass over it, but it is also intended to provide minimal obstruction to other animals.

Small quantities are in stock and can be shipped in 3 days from an order. For larger projects it may take up to 2 months to receive an order.

The ACO Tunnels must be installed with a concrete surround as shown in the installation instructions. Attention should be paid to the subterranean water drainage to ensure no hive frost occurs in the winter time. At the crown or the road, the gap formed at the top between the tunnel modules should either be filled with mastic or the modules can be slightly grinded before set up to ensure no gap.

ACO. we care for water