As necessary as road works are for the improvement of the road conditions, any type of maintenance next to or on the vehicle drive path poses a hazard. Water filled barriers are one of many road safety devices that can help to improve safety at maintenance spots along national and urban roads.

In this article, we explain what these barriers are, why the devices are important, where else these devices are used, and which additional road safety products can be used to improve roadside work sites in South Africa.

What are water filled barriers?

As the name suggests, these are barricades that prevent vehicles from moving into hazardous areas. The devices have a modular design to allow for placement as required. With an interlocking design, the units can be connected to each other to create a temporary wall around a hazard or along the edge of the road.

These should not be confused with crash barriers. Although filling with water helps to stabilise the units, prevent the devices from being blown over or easily moved, the units are not stacked behind each other as is the case with crash cushions.

With crash cushions, bags or modular units are filled with water or sand and stacked behind each other to slow down vehicles that have lost control over their brake systems. Each unit absorbs some of the kinetic impact energy until the vehicle comes to a stop. With the water filled units, the water as mentioned, serves to prevent easy movement.

Make-up of water filled barriers

Each unit is made from high impact Polyethylene, which is also UV stabilised. This ensures that the units are durable and able to handle the harsh sunlight without easy fading or cracking. Because the products are made from polyethylene, they are not affected by oxidation as is the case with untreated steel. This adds to their sustainability profile. Of course, being made from polyethylene also adds to their lightweight profile.

The ones we supply are available as 6 kg, 17 kg and 28 kg when empty. The 28 kg units only weigh 80 kg when filled. This is quite heavy for one person to move, as is the aim. But when empty, the unit is lightweight enough to lift up and stack onto other units without needing special lift equipment. To drain it from water is also a straightforward process.

We offer the bright yellow types because of the high visibility offered by yellow. Motorists in South Africa also associate yellow with road works and construction. This familiarity with the colour helps them to immediately recognise that some type of hazard can be expected at the other side of the barrier.

How the water-filled barriers are used

Units can be deployed separately or as interlocked units that form a wall. Apart from acting as temporary safeguarding areas by creating highly visible barricades around the areas where workers operate, the units serve to:

  • Warn motorists of impending hazards.
  • Create boundaries in the form of temporary walls at the edge of roads to give motorists more confidence to drive around hazards.
  • Create drive paths to redirect motorists or to channel vehicles into single or double lanes.

Besides being used for road works, these temporary barricades are often used for the following purposes:

  • Events to demarcate spectator areas and payment lines.
  • Sport events to demarcate cycle paths or sport playing areas.
  • Open manholes on pavements to prevent accidental falling into the manholes.
  • Shopping centres to create boundaries around wet areas or construction work.
  • Construction sites to prevent people from entering work-in-progress areas.
  • Accident scenes to create alternative routes around scenes, which take a considerable time to clear up.
  • Parking areas to prevent motorists from using disabled parking spaces without authorisation.
  • Urban roads to create boundaries between two opposite flowing lanes.
  • Unrest incidents where law enforcement agents use the devices to barricade areas.
  • Stop-go areas where one unit is used at a time to indicate that the path is closed until the operator moves it to allow vehicles to move.
  • Roadblocks to prevent motorists from simply driving on without permission.

From the many applications, it becomes clear that water filled barriers are exceptionally useful devices. Reasons for this include:

  • Lightweight design that facilitates easy and fast deployment without special equipment.
  • Modular design for using as few or many as needed.
  • Stackable for using less storage space, also making it easier to transport.
  • Durable materials with no maintenance needed, giving the devices a long service life and subsequent low cost of ownership.
  • New design includes see-through holes, which provide for grip when having to lift the devices while also making it possible for the wind to blow through instead of the devices having to withstand strong winds.
  • Superb visibility at night because of the bright colours.
  • Different sizes to meet application requirements.

Why use these devices?

Collision with these barriers causes less damage than would be the case with a concrete or steel barrier. By using water filled devices at road work zones, the risk of injury to workers can be considerably reduced. Unfortunately, many people lose their lives while performing road maintenance tasks simply because they are not visible enough and don’t have the benefit of a temporary boundary to show motorists where they can drive. Adding these devices to your road safety product budget for such maintenance projects can help to improve the work safety profile of your maintenance crew.

Warning against incorrect usage

Incorrect usage of the devices can lead to accidents and injuries. More often than not, the barricades are placed without interlocking the units or without filling the devices with water. This makes them less stable than filled ones when exposed to windy conditions. Also, not interlocking the units affects their efficiency as walls. If one unit is moved out of position, it can become a hazardous obstacle in the path of road users. As with any road safety products, it is essential to use the devices according to manufacturer guidelines to ensure optimal performance.

Sustainability character of water filled barriers

Because the units are made from a type of plastic, the devices can be manufactured from recyclable material. At the end of their lifetime, the devices can again be recycled to make other types of devices. With such, it is possible to keep the environmental impact low.

Related road safety products

Apart from the larger, yet, easy to deploy water filled units, road maintenance and construction crews can deploy the following temporary application devices to improve safety of the area:

  • Traffic cones
  • Delineators
  • Truck-mounted attenuators

Traffic cones

These are shaped like inverted cones and are often called witch hats because of their shapes. The cones are available in many sizes and colours. It is possible to fit them with reflective strips to make them even more visible in low-light conditions. Pylons are also stackable, lightweight in design with heavy bases to prevent them from blowing over in slightly windy conditions, and easy to deploy. A single worker can deploy several cones quickly around a work zone. The pylons are used at accident scenes, for sport activities to act as obstacles or to demarcate playing areas, and in front of wet areas in shopping malls. Many more applications exist. Read more about the traffic cones available and the applicable uses of the pylons.


These consist of black and yellow striped blades fitted onto bases. The devices are placed around work sites, and like cones or water-filled barriers, serve to demarcate safe drive paths, channel vehicles and warn of hazardous conditions. The devices are highly visible and can withstand several bumps before replacement is necessary. This is because of their unique design that makes it possible for the blade to bend backwards upon impact from a vehicle. Once the vehicle is over the device, the blade returns to its upright position. Read more about the functions and types of delineators.

Truck mounted attenuators

These devices are mounted at the rear end of trucks and serve to protect workers and expensive equipment from high-speed collision impact from speeding vehicles. The truck is parked at the beginning of the road works where machines operate. Instead of a vehicle colliding with the machinery, it hits the attenuator on the truck. Read more about truck mounted attenuators.

Wrapping up

Water filled barriers can be used as standalone devices or in conjunction with other road safety products to improve the safety conditions at construction or road maintenance sites, reduce the risk of accidents related to hazards on the road, and channel vehicles safely around the obstacles or maintenance areas. These devices are versatile and durable. Take a closer look at these road safety products as available from Armco Superlite.