Security

Concrete safety barriers

The Highways Agency has determined that only the concrete step barrier should be installed on all motorways where the Average Annual Daily Traffic (AADT) exceeds 25,000 vehicles per day. It is safer, more reliable and more sustainable.

The concrete step barrier is effective in preventing that most dangerous of all motorway accidents: the crossover. Crossover accidents occur when a vehicle crashes through the central reservation and into the path of oncoming traffic.

The concrete step barrier is designed and tested to an H2 containment standard, which means that it is capable of restraining vehicles of up to 13 tonnes in weight. This includes vehicles such as coaches, 4x4s and light vans. In comparison, the steel barriers that currently serve motorway central reserves have a containment level of N2 which is only able to contain cars of up to 1.5 tonnes.

The concrete barrier is designed to be repair and maintenance-free for the entirety of a minimum 50 year lifespan. By contrast, steel barriers, have a design life of only 20 years, and also need regular tensioning and maintenance as well as being replaced whenever any impact occurs.

So far lengths of new step barrier have been installed on the M1, M5, M6, M18, M27, M62 and M180. Lengths of concrete step barrier have also been installed on the A1, A12 and A27 as well as the A55 in North Wales.

Sustainable benefits

In addition to the safety advantages, the concrete step barrier has particular sustainability benefits. A recent study concluded that the benefits of the concrete barrier include:

  • Reduced traffic congestion and associated emissions
  • 80 per cent less embodied CO2 used to manufacture concrete barriers compared with steel barrier systems
  • No need for any additional protective coatings
  • Fully recyclable
  • Virtually maintenance-free over the 50 year design life
  • Enhanced road user and worker safety.

The concrete step barrier is designed and tested to an H2 containment standard, which means that it is capable of restraining vehicles of up to 13 tonnes in weight. This includes vehicles such as coaches, 4x4s and light vans.

Concrete proof

Real sustainability is about long-term holistic solutions rather than short-term headlines. The projects within this brochure show how concrete’s range of built-in benefits combine to offer a long-term solution that has minimum need for additional preservatives or finishes. In addition, concrete is a locally sourced material from within the UK, it is long-lasting and virtually maintenance-free and at the end of its life can be fully recycled.

Publication

This is Concrete - Ten Years, Ten Insights