Design of Truck Arrester Beds

1. Purpose

Truck Arrester Beds are used to provide a safe ' escape route' for runaway heavy vehicles and comprise a bed of lightweight spherical aggregate placed in a strategic location towards the bottom of a long steep descent.

Damage to heavy vehicles using an arrester bed is minimal, especially in comparison to the damage caused in a crash. The heavy vehicle is safely decelerated and stopped by the drag caused by the vehicle as it sinks into the bed material. Where possible, if the arrester bed is able to be sloped upwards the force of gravity will assist the safe stopping of the vehicle.

In a project, the need for a Truck Arrester Bed should be determined by a risk analysis before design. Consideration should also be given to the most suitable location for an  Arrester Bed in order to mitigate risks to all motorists

1.1 Liaison with other Authorities & Possible Stakeholders

Authorities with which liaison may be necessary, include:

Service Authorities	​Emergency Bodies
​Western Power Water Corporation Alinta Gas Telstra, & other communication authorities	​RAC Police Service Fire & Rescue

   

Government Authorities	​Main Roads
Local Government Authority Ministry of Planning Transperth Environmental Protection Authority	​Transport Branch Pavement and Structures Branch Asset Manager Term Network Contractors

 

2. Issues to Consider in Truck Arrester Bed Design

Authorities with which liaison may be necessary include:

​Design & Planning	​Road Side Facilities
​Risk Assessment	​Specific Provision for Cyclists
​Geometric Design	​Specific Provision for Pedestrians
​Drainage - Stormwater	​Arrester Bed Emergency Phones & Location
​Lighting, both Street & Arrester Bed	​Bus Stops
​Site Investigation	​Public Utilities
​Service Relocations	​Emergency Retrieval Vehicle Work Space
​Environmental Management Plans	​Landscaping
​Environmental Constraints e.g. Chemical spills	​Emergency Retrieval Vehicle Parking
​Environmental Assessment	​Driveways
​Fencing/Guardrail Requirements	​
​Emergency Procedures	​
​Aggregate Quality Specifications	​
​Aggregate Material Specifications from Main Roads Pavement & Structures Branch	​
​Anchor Points for Truck Retrieval	​

Signing​

• Advance Directions Signs
• Entrance Signs
• Emergency Procedure Signs
• Site Specific Signs
• Gravel Spill Hazard Sign
• Kerbside Standing Restrictions

2.1 Further Design Aspects to Consider

• Location of Emergency Roadside Phone that is easily accessible after an incident.
• The location of Signs and Street Lighting poles shall not obstruct the entrance of the arrester bed. Routine maintenance of the light poles shall not impose any entry restriction to the arrester bed at any time.
• Overhead power lines should not restrict operations of lifting cranes when trucks are retrieved.
• Proposed emergency and maintenance vehicle parking shall be located such that no obstruction occurs on the entry of the arrester bed.
• Allow for a work space for heavy vehicle removal. Eg. Lifting Cranes
• Emergency Contact & Procedures shall be prepared for each site. The designer should liaise with Police, Fire Brigade and Ambulance services , Term Network Contract (TNC), Traffic Control Infrastructure Contract (TCIC) and local council.
• Where a spill of gravel may impinge on normal traffic lanes or adjacent footpaths or cycleways then a warning sign must be installed near the hazard.

3. Operational Procedures

• Integrity of Arrester Bed structure
• Clearance of spilt gravel
• Clearance to near by drains that may catch spilt gravel
• Gates, and who will receive the gate keys for various maintenance functions
• Fences
• Phones
• Landscaping
• Signs

3.1 Sample Signs & Emergency Procedures

3.1.1 Typical Sign Details

Signs typically installed at Truck Arrester Bed are listed below.  An assessment should be made as to what information should be included on this sign and risks assessed as to whether a 12 hour turn around time for the truck arrester bed is suitable.  (For example truck routes that carry grain carts in peak season may present a shorter risk tolerance.)

• Use T3-14 (Loose Surface) - refer AS1742.3
• 9420-0121    Arrester Bed 1km
• 9420-0122    Arrester Bed 300 m
• 9420-0124    Arrester Bed
• 9531-1042    Arrester Bed Truck Removal

Signs at Truck Arrester Bed sites should be tailored to each project.

3.1.2 Sample Emergency Procedures

Emergency Procedures are required for all Truck Arrester Beds and to cater for  incidents that may have further risks, like toxic spills. The RAC has existing emergency procedures which are followed once they have been contacted via the emergency phones located at Truck Arrester Beds sites.

In the Metropolitan area an emergency phone will automatically contact RAC - who then contact the police, who will contact other emergency services if required, according to the site arrangements.  For example  the RAC Emergency Procedures for the Truck Arrester Bed  at Greenmount are:

• There is an emergency phone placed at the Truck Arrester Bed in Greenmount.
• This Emergency phone is designated as Box EB 898 and is located on the Great Eastern Hwy in Greenmount near the corner of Woolowra Rd Map 253 D5.
• For those of you that do not know what a truck arrester bed is, it is a long trench filled with special material. If the truck is unable to stop for what ever reason the driver drives into this trench and comes to a safe halt.
• On any occasion that a truck has cause to use the arrester bed and uses the telephone to call for assistance we are to immediately contact the Police Department on 9222 111 and the Main Roads on 9311 8333.
• Trucks which weigh under 22.5 tonnes may be removed by tow trucks anything that is over this is likely to need a crane to assist in its removal.
• Currently our Heavy Goods Tow Contractor is Daynight.

Other contacts that may be required at an emergency scene or who need to be contacted are:

• Police
• Fire & Rescue
• Main Roads Term Network Contractors
• Main Roads Operations Centre
• Main Roads Asset Managers