What are Wildlife Guards?

A wildlife guard is a small bridge like assembly, installed into a roadway that discourages wildlife such as deer, elk, and bears from crossing through an roadway break in a fence, while still allowing traffic to move through. Wildlife guards are installed inline with Wildlife fencing, that is commonly found on the side of interstate and highways in the US. 

Why are Wildlife Guards needed?

Throughout the past few decades, state departments of transportation have began to utilize wildlife fencing on the side their highways to prevent wildlife migration across the highways. This has been a tactic used to reduce the number of wildlife related car accidents on US highways. 

After installation of miles upon miles of wildlife fence across the United States, some state departments of transportation have discovered that the wildlife is very determined to cross the road. Wildlife has been found to find the openings left for roadways in the fence line as an access point to move across the road. The downside is now the wildlife fences have become a trap for the wildlife, as the migrating animals become lost and do not know how to exit the highway on the otherside. 

While this does not render the fences as completely innefective, it does not completely solve the problem. Additionally, now the only points of entry that the wildlife uses, is now at highway interchanges, where drivers passing under an overpass cannot see to their right and may not be able to see approaching wildlife as easily. Resulting in high velocity impacts.  

An improvement to existing wildlife mitigation measures

States such as Colorado and Wyoming have begun to implement Wildlife Guards into their highway designs, closing the compromised opening in the wildlife fencing and discouraging wildlife from crossing onto an active highway.

Cattle Guard vs Wildlife Guard

Many of us are familiar with a cattle guard, which is a small assembly of angle iron or bars that farmers, ranchers, and the United States Forest Service use to keep cattle in a fenced area, but allow for an opening for vehicles to cross. Since deer are well known for how far they can jump, a simple cattle guard is innefective at preventing wildlife crossing. Wildlife guards must span a much further distance, approximately 16ft, to be effective at preventing wildlife crossing. Since this span is much greater, wildlife guards need to be engineered as a bridge crossing, to allow for heavy loads such as semi trucks to effectively cross the guard. This is a reason why a wildlife guard is also refered to as a deer guard. 

A typical cattle guard installation. Famartin, CC BY-SA 4.0 <https://creativecommons.org/licenses/by-sa/4.0>, via Wikimedia Commons

Engineered Wildlife Guard Construction

A wildlife guard must be engineered and rated to be safe for use on public roadways. Considerations for drainage must also occur. The common design for a wildlife guard is to use rated bridge decking sitting on top of channel and wide flange beams. When Bear Iron Works is involved with procurement and installation of a Wildlife Guard, we recommend using Mission Critical Solutions pre-engineered bridge decking. This product meets Buy American requirements for federal projects and we have a good working relationship with them to move the project forward as fast as possible.

The decking is open, so any water will fall through the decking and must be captured. The wildlife guards typically sit on top of a pre-cast concrete drainage structure and ties into a stormwater system. Between the pre-cast and the wildlife guard itself are rubber bearing pads, that allow for even distribution of loads onto the pre-cast concrete. Lastly, the wildlife guards are securely bolted down to the pre-cast pad, to prevent any movement. 

Wildlife Guard Installation

Bear Iron Works has experience installing wildlife guards, as it is a delicate and technical process. Due to the common engineering methods and size of the wildlife guards, the wildlife guard comes in multiple pieces. Each piece must be pre-assemble on blocks above the pre-cast concrete structure. The assembly must be bolted together into once piece, as the underside is inaccessible once the guard is installed. 

Once the steel bolts are all in place a multi point pick with 2 taglines is required to lift the wildlife guard up, remove the blocking, and set it in place. Once the guard is in place, anchor bolts must be drilled and installed into the pre-cast concrete. Bear Iron Works recommends drop-in anchors for your design basis, as the preparation work for epoxy anchors becomes difficult with the guard in place and takes more time for installation. Once the anchors are installed, hold down tabs are installed and bolted tight to hold the wildlife guard in place. 

How long does it take to install Wildlife Guards?

A 16 ft x 30 ft wildlife guard, galvanized, using drop in anchors will take 1-2 days to install on top of the pre-cast concrete. 

The pre-cast concrete will take 1-2 days to install after finish grading has been completed. 

Finish grading will depend on existing conditions of the project. 

Wildlife guards can take anywhere from 10-12 weeks to fabricate, galvanize, and ship. So make sure you plan for adequate lead times in your project schedule.

Pre-cast concrete can take 6-10 weeks depending on the backlog of the pre-cast concrete companies. 

Bear Iron Works - Turnkey Wildlife Guard Installation

If you want to make the widllife guard scope of your project easy, consider specifiying Bear Iron Works as a designated installer. Activities included:

• Shop drawing submittals
• Procurement of grid decking
• Fabrication and galvanization of wildlife guards
• Wildlife Guard installation
• Pre-Cast concrete procurement
• Pre-cast concrete installation
  
• QA/QC management along the entire process
• Scheduling and coordination

Need other scopes of work done? We can complete the following scopes with our partners:

• Excavation and grading
• Storm drain installation
• Stormwater Management Plan Compliance

That's the benefit of working with a company like Bear Iron Works, excavation contractors turned manufactures that are experts with both dirt and iron. We have professional project managers on staff, here to help your project run sucessfully. We know the process because we've done the process. See this picture of our President and Vice President doing an install themselves, so we can confidentally know how to manage the process.