S-A-B

Central reservation longitudinal side impact crash barriers on dual carriageways may often have openings or gaps in them at 2 to 4 km intervals which allow for the emergency vehicles to cross over . The advantages of these gaps is that they also help to divert road traffic when accidents occur or maintenance road works are underway. However the open gaps can cause major accidents because of drivers attempting to ‘U’ turn through them or driving through them to avoid a possible vehicle collision . Some drivers have been known to drive through the open gaps and continue to drive the wrong way down the adjoining carriageway with terrible accident results. If the gaps are closed up they can't be used for emergency vehicles and traffic diversions or for maintenance situations.

The S-A-B^® is a special high containment modular barrier studied to protect the gaps. The removable barrier placed between ends of exhisting barriers can be partially or totally opened in few minutes.

The modules are about 4 m long and are easy connected with pins to each other. The end terminals are fixed to the ground and have lateral connections to all types of usual barriers, steel or concrete.

Each module is composed by 3-beam steel panels. The sides of the module are joined by strong steel supports which include the mounting supports for the pins and the removable frame posts.

The wheel units are located between the side panels and are lowered to the ground when the barrier is opened.

The S-A-B^® is designed so that the system can be totally or partially opened to get a quick emergency route or to provide a two lane traffic diversion contra-flow route for traffic. The S-A-B^® removable barrier can be opened by 2-3 workers in a few minutes without any special tools.

Diagrams of opening (PDF)

The S-A-B^® has been tested using a 13,000 kg bus (class H2) and the working width was about 1 m and the bus was only slightly damaged.

The severity for vehicle occupants ASI=1 was calculated during the 900 Kg car crash test and no windows in the car were shattered.

The S-A-B^® removable barrier meets the requirements of EN 1317- 2 - 4 (chapter 6) at the TB51 and TB 11 test levels.

FAQ about opening gaps

Technical drawings (PDF).