A guide to bollards and bollard spacing

When conducting a site survey, it's important to evaluate the surrounding environment, and whether the site has vehicle access, is located close to road traffic, and the type of vehicular activity that occurs in the vicinity. This is a critical step in understanding the risks to the buildings and the people who use them.

Specifying security bollards may be the solution for your project in mitigating the range of vehicle-related threats out there, including speeding drivers and vehicle attacks. However, identifying the potential risks and a site’s vulnerabilities are just the first step: there are many different types of bollards available, such as timber, stainless steel, crash rated, low impact, fixed and removable or rising bollards.

Choosing the appropriate bollard design is essential in creating a controlled traffic setting that enhances pedestrian and building safety for all.

WHY SHOULD BOLLARDS BE INSTALLED?

There are many reasons for installing a bollard array:

They deny permission to drive into an area, such as around open landscapes, monuments or even inside open buildings

They can be used where demarcation is required to keep pedestrians safe from vehicles, in situations where a fence or pedestrian guard rail would be unsuitable and direct access through the line by pedestrians is required

Removable or rising bollards restrict vehicular movement during specific hours or until permission for access is granted

They prevent vehicles from accidentally clipping or driving into property/buildings

Hostile Vehicle Mitigation (HVM) bollards protect high-security sites and public sites from terrorist attacks

When designing a bollard array, it’s important to note there are no strict guidelines, with the correct spacing varying depending on the application. The rule of basic common sense applies, with a distance of 1.2 metres used for most applications but some bollards especially crash rated will have specifications from the manufacturer.

CRASH-RATED AND NON-CRASH RATED BOLLARDS

Security bollards can be generally split into two categories: crash-rated and non-crash rated. Crash-rated bollards have been put through rigorous testing by government-approved bodies and given different ratings depending on their levels of resistance.

In the UK, PAS 68 is the Publicly Available Specification for vehicle security barriers and is considered to be the security industry’s benchmark for HVM equipment. Crash-rated bollards are becoming increasingly common in and around cities.

Non-crash rated bollards are not designed to be resistant to vehicle crashes, although this doesn’t mean they have no resistance. Their resistance power has simply been untested. They are typically installed at low-risk sites or where security isn’t a main concern.

PEDESTRIAN FLOW

Understanding pedestrian movement is key to a successful bollard arrangement. Designers should be careful when installing bollards to ensure an appropriate level of physical protection is provided with minimal impact on pedestrian flow. The government guidelines state:

Sites must accommodate safe, comfortable and convenient pedestrian movement when installing bollards

Bollards should be installed away from a site’s natural pinch points

They should not be placed where pedestrian conflicts are likely to occur, such as areas of limited visibility

The height and visibility of bollards must be considered, especially in low-light conditions and rush-hour peaks

Pedestrian movement is affected by several factors: Route Capacity (the rate at which pedestrians can safely pass through a space during a defined period), Comfort (the amount of personal space available to pedestrians and the ability to move freely), Convenience (the ability of a person to follow their preferred route at their favoured speed) and Conflict (an event that alters the natural flow of movement).

These issues need to be taken into account to predict how pedestrian movement will be influenced by a bollard scheme.

Finally, it’s essential to consider whether the bollards can cause problems for wheelchair users and people who are visually impaired. This is in accordance with The Disability Act 1995, which gives disabled people a right of access to goods, facilities, services and premises.

The government advises:

The absolute minimum between obstacles (such as bollards) should be 1000mm; this will be enough to allow wheelchair users to pass comfortably. The maximum spacing should be 1200mm.

The positioning of bollards should be consistent and away from general lines of movement

Bollards should be at least 500mm away from the edge of roads and increased to 1000mm where there is a severe edge or camber

Be mindful of blind and partially sighted people when linking bollards with chain or rope as this can be a hazard

For more advice and information on choosing the perfect bollards for your site, contact Jacksons Fencing today.