Do you know what traffic bollards are? In today’s guide, we will discuss bollard types and introduce the four main uses of traffic bollards. Read on for more information.
1. Types of traffic bollards
Traffic bollards come in four main types:
- Embedded Bollards
- Surface Mounted Bollards
- Rebounding Bollards
- Retractable / Removable Bollards
- Single Flexible Bollard
Each type is specifically designed for its purpose and has its own benefits and limitations. Within those groups, there are sub-groups which I will discuss as well. Also, bollards that fit in those categories can also fall into other sub-categories less dependent on function and more on aesthetics. Architectural Bollards might be any of the above but are also designed to include pleasant or unique shapes. A Lighted Bollard is simply a bollard with a light source built in either to add conspicuity to the bollard or to light the surrounding area.
1) Embedded Bollards
Embedded Bollards are simply bollards that are embedded deep into the ground. This is usually for added strength and security. Bollard or guard rail manufacturers can make embedded bollards from a variety of materials, be it steel, concrete, or even wood, however, the bollard will only be as strong as the foundation in which it is buried.
A steel post filled with concrete and buried very deep within a reinforced concrete foundation will be strong indeed. On the contrary, a wooden post buried in soft sand or dirt will not provide as much protection.
Costs for this type of bollard can be significant when coring out existing concrete or asphalt surfaces. It also potentially weakens the foundation, and therefore may not even be appropriate in an application such as a structural concrete parking deck. On the other hand, when placing a bollard in an unpaved area, this is perhaps the least expensive and simplest approach.
2) Surface Mounted Bollards
This type of bollard uses some sort of anchor system, usually mechanical, to mount the bollard to the surface. Although this is an inexpensive method of installation, it also is not a very secure method. Upon impact, the anchors are often the weakest link and quickly give way, leaving a tilted bollard and damaged foundation.
However, when the purpose of the bollard is more to provide a mere presence or psychological barrier, this type of installation is most cost-effective. It also may be necessary to use shear bolts in a post-tensioned concrete structure in order to prevent impact to the bollard from potentially compromising the building.
The next type of bollard, the rebounding bollard, is often surface-mounted but overcomes the strength and damage issues associated with standard surface-mounted bollards.
3) Rebounding Bollards
A relative newcomer to the bollard field, rebounding bollards use energy absorption technology to provide the strength of some embedded bollards, with the low installation costs and flexibility of surface-mounted bollards. When a rebounding bollard is impacted, it is allowed to tilt as some mechanism, be it an elastomer or spring system, more slowly absorbs and dissipates the energy of the vehicle.
The bollard then ideally returns to its original position undamaged and fully functional. Some barriers use advanced polymers that do not yield like metal or concrete might under extreme load.
A further advantage of this type of system is that damage to vehicles, passengers, and loads is reduced due to the more gradual absorption of impact energy. Imagine crashing a vehicle into a large concrete bollard. Since there is almost no give, it is much like hitting the proverbial brick wall; all energy is immediately felt by the vehicle and its passengers. With a flexible bollard system, that energy might be dispersed over several hundred milliseconds. While that doesn’t sound like much, it makes a great deal of difference to the peak forces felt.
Some bollards of this type are actually not intended to provide traffic denial capabilities at all. As such, they are used mainly as sign markers and psychological barriers. These are extremely prevalent in the United Kingdom.
4) Retractable / Removable Bollards
Not all applications for bollards are intended to be permanent or always prevent access. As such, retractable and removable bollards have been designed to allow the owner or a potential traveler to access the area normally denied by the bollard.
This is typically done in one of several ways. The lowest technology is the pipe-in-a-tube method where a socket is created in the ground. The bollard can then be removed from the socket when access is to be granted. This is inexpensive but requires manual intervention to access the area. A second way is through the use of pivoting bollards.
A locking pin is used to hold the bollard upright under normal circumstances and removed to allow the bollard to lay flat when a vehicle is to pass over it. These bollards are generally flat in shape to allow for vehicle clearance. Often, the pin is locked in place with a padlock to prevent unauthorized access.
Finally, the most expensive method is the automatic retractable bollard. Usually hydraulic-powered, the bollard actually retracts straight down into the ground and becomes flush with the surface during access. Actuation of a hydraulic bollard can be done by any number of methods, from security guard push buttons to remote controls and toll booth pay systems.
5) Single Flexible Bollard
Flexible Bollards Offer Highly Visible, Durable Protection. Ranging from 31.5–40 inches high and 3–4 inches in diameter, and available in six colors, flexible bollards stand out in the streetscape. Optional reflective tape in four available colors can be added to the top of the bollards for even more of a visual pop. When compared to traffic cones or slender plastic delineators on spring hinges, sturdy flexible bollards provide a longer-term solution. They will not be as easily damaged or pulled out of place in high-traffic areas, saving time and money over the course of their lifetimes.
2. Uses of Bollards
The next four parts of this article will discuss ideal uses for bollards for each of the following areas of concern:
Traffic Denial
Parking Lot Protection
Drive-Thru Lanes
Factories and Warehouses
Certain types of bollards discussed today are more or less appropriate for each application, depending on the required function. That will be discussed in detail for each.
3. Conclusion
This guide summarizes five types of traffic bollards and their applications. Hopefully, after reading this article, you will be able to find the right safety barrier manufacturer and purchase the right barrier.