What Is a Bollard?
A bollard, also known as a car stop, is defined as a “fence or barrier on a road.” Generally shaped like cylindrical posts, bollards are installed perpendicular to the ground. They are often placed at intersections, near pedestrian crossings, or at the openings of intersections with the primary aim of preventing human casualties. Bollards prevent vehicles from encroaching onto sidewalks, thereby enhancing safety.
Types of Bollards
There are two main types of bollards.
1. N-Type Bollards
N-type bollards are non-collision-resistant accessories used to deter vehicles from entering specific areas. They are also employed to separate pedestrian and vehicular traffic at intersections. While similar to pedestrian and bicycle fences in maintaining pedestrian traffic, N-shaped bollards specifically prevent pedestrian crossings.
2. H-Shaped Bollards
H-shaped bollards are impact-resistant and used to prevent vehicle entry. They are typically installed to demarcate openings, similarly to N-shaped bollards. In cases where a series of vehicle barriers cannot be installed, H-shaped bollards serve as a supplementary measure.
Bollards Installation Criteria
The installation of bollards is categorized into N-type and H-type, each with specific criteria.
1. N-Type Bollards
N-type bollards are installed in areas with low vehicle speed and high pedestrian traffic. They are typically used where the road width is narrow, visual distinction is possible, and pedestrian safety can be ensured. The height of N-type bollards should not exceed 0.85 m to maintain visibility for both vehicles and pedestrians.
2. H-Shaped Bollards
H-shaped bollards are installed on roads with high pedestrian risk, high vehicle speeds, or poor visibility. They are crucial for safety, especially where pedestrians are likely to gather. The height of H-shaped bollards should be between 2 and 3 feet, considering vehicle bumper heights, which vary depending on the type of vehicle.
Type HC
Type HC bollards are installed for vehicles with a mass of 1.8 tons, collision speeds of 20 m/h or more, and entry angles to the sidewalk of 15 degrees.
Class HB
HB bollards are for vehicles with a mass of 1.8 tons, collision speeds of 25 m/h or more, and entry angles to the sidewalk of 15 degrees.
Location of Bollards
Bollards are typically installed after considering road and traffic conditions, as well as past accidents. The need for bollards varies by region and requires a comprehensive decision based on regional needs and safety inspection results. For H-shaped bollards, the distance between them must be less than 1.5 meters to prevent vehicles from slipping through.
Additionally, when considering sidewalk users, including those in wheelchairs, with canes, or bicycles, appropriate widths must be ensured. For wheelchair access, a width of approximately 3 feet is required, while cane users need about 4 feet. In snowy areas, a minimum width of 3 feet is necessary, along with considerations for snow removal operations and pedestrian safety.