Plastic highway barriers are typically lighter than those constructed from wood and aluminum and are significantly lighter than concrete barriers. While this relatively lighter weight makes them easier to transport and reposition, it also means that they are more prone to being blown around by the wind or knocked over by passing vehicles. This problem can be mitigated, however, by filling the barriers partially or completely with water. This extra weight and support can make them as heavy as or heavier than wooden and aluminum barriers; however, they are still significantly lighter than concrete barriers.
Because they are intended for use in highway construction settings, surrounded by traffic, highway barriers are in constant danger of being run into by cars, semis and road construction machinery. For this reason, durability is an important consideration when selecting a barrier. Plastic barriers, while more flexible and resilient than than wood and aluminum highway barriers, are significantly less durable than concrete barriers.
A consideration of the pros and cons of plastic barriers must take into consideration the competing safety concerns. Plastic barriers are generally not designed to redirect a vehicle, meaning that a vehicle colliding with the barriers will pass through them along roughly the same path. While this reduces the risk of injury to vehicle occupants relative to a collision with a concrete barrier designed to stop or redirect vehicles, it can make road construction more hazardous to crews who may be positioned behind the barriers. Such road crews would likely be better protected by a firm concrete barrier.
