Roadside conditions that are shielded by a roadside barrier can generally be placed into one of two basic categories: (1) embankments or (2) roadside obstacles.
Consider embankment height and slope when determining if a barrier is warranted. Which would be cheaper, installing and maintaining a guardrail, or permanently creating a safer roadside by regrading the side slopes? Roadside barriers perform most effectively when they are installed on slopes of 1V:10H or flatter. Caution should be taken when considering installations on slopes as steep as 1V:6H and any such installation should be offset so the vehicle is in its normal altitude at the time of impact. Consider the installation costs of the barrier, life cycle costs of maintaining the barrier, and crash costs.
Barrier Warrants for Bodies of Water
Consider barriers when bodies of water greater than 2 feet deep are located within a clear zone.
Other Barrier Considerations
In some instances where barrier is warranted, installing guardrail may appear to be a less expensive option than removing or relocating a hazard. Consider the installation costs of the barrier, life cycle costs of maintaining the barrier, and crash costs.