Choosing Bollards

Bollard Functions

Bollards can serve many functions: security, pedestrian safety, demarcation or just to hold a sign. Depending on the function the bollard, the strength of the pipe and the method of installation will vary. We may categorize bollard types in many ways, but here we are choosing to divide bollards into two groups, Passive and Active. Passive Bollards generally serve a non-critical function and are designed with collision mitigation in mind. In contrast, Active Bollards are designed to stop vehicles to the best of their ability with consequences to colliding vehicles, a secondary concern at best.

Passive Bollards

A Passive Bollard is often in the middle of a parking lot and isn’t protecting anything beyond itself. It may serve to hold a sign post and non-critical sign or simply serve as a delineator for traffic control. Passive Bollards should be robust enough to take frequent bumps and taps from vehicles, but for safety of drivers, may be designed to fail in a moderate accidental collision.

Choosing Bollard Pipe for Passive Bollards

For a Passive Bollard, 6” Schedule 40 Pipe Bollards are often chosen. Although you aren’t trying to stop a fast moving vehicle, these have enough weight (inertia) to handle frequent light bumps. Sometimes, for economy, 4” Schedule 40 Pipe Bollards are chosen and may perform well indefinitely if they aren’t getting knocked frequently. They have a tendency to bend over time if getting lightly bumped often.

Passive Bollards without Concrete Footing

There is a good argument to be made for no-concrete footing installations where the bollard pipe is set into compacted gravel, but is still filled with concrete as is normal, and then asphalt is patched.

When a bollard (or several) sits in the middle of a parking lot where vehicles often take a carefree shortcut across parking lanes, it can sometimes go unnoticed by a driver, resulting in a head on collision. Ouch! (sunlight blindness from a low setting sun can be an excuse). If this is an “Active Bollard” (described next) with robust footing, the vehicle and driver could take some real damage. And for the business, an expensive repair. A bollard without a concrete footing is a lot cheaper to replace, or may even by straight enough to reuse and repair.

Active Bollards

An ideal Active Bollard would remain upright through any collision and never have any damage. In the real world we always have budgets, so it becomes necessary to determine the Best Acitve Bollard for the application.

One place where an Active Bollard might be crucial in the parking lot is to hold a stop sign since having one plowed over is an accident waiting to happen. But more often, an Active Bollard serves to stop a vehicle from “penetrating” some boundary, to the best of its ability. In general, the value of what lies beyond the boundary warrants an arbitrary amount of damage inflicted upon the violating vehicle and occupants.

Where to Use Active Bollards

The reasons these arbitrarily immobile bollards may be rationalized is that, beyond the boundary lies either:

• Pedestrian area where a collision could lead to injury or death. This includes sidewalks, pedestrian walking lanes or paths and building entrances.
• Another obstacle, a collision with which would otherwise stop the vehicle anyway, but result in more expensive damage to site owner. (e.g. corner of a building, dumpster enclosure).
• A utility, where a collision could be dangerous, costly and maybe catastrophic (e.g. Gas Meter, Propane Tank, Gas Pump, Electrical Cabinet, Fire Hydrant.)
• A building entrance or vulnerable areas on a building’s exterior (e.g. wall of window). Yes, the driver’s would probably endure less injury from driving into the entrance glass doors or glass wall, but you have a right to protect your property, and a duty to protect people in and around the building.

Maximizing Bollard Strength

When you are protecting pedestrians from vehicles, you have good reason to make the bollards as impenetrable as the budget affords.Likewise, your building entrances may be protected with impenetrable bollards as long as they are sufficiently offset from lot traffic. For example, a bollard barrier may be set back a couple feet or more from a curb to avoid accidental lateral collisions, but still out far enough from doors to maximize the footprint of pedestrian protection.

Bollard Pipe for General Active Bollard Applications

Most often, 6” Schedule 40 is used for Active Bollards designed for accidental collisions, but 6″ Schedule 80 with the thicker wall is also sometimes chosen.

Choosing Bollards For Store Front Protection

At a bare minimum, use 6″ Schedule 40 pipe with 18″ diameter, 48″ deep footings. This should stop or deter the average ram-raid in a car. If it is a concern that someone would use a heavy truck at significant speed, then you may want to beef up the bollards by using 8″ Schedule 40 or 80. For a serious barrier, you can use 10″ Schedule 40 Pipe or larger or even use Impact-Rated Crash Bollards (they are outside the scope of this article).