Important OSOM requirements that are sometimes overlooked

IMPORTANT OVER SIZE OVER MASS (OSOM) REQUIREMENTS THAT ARE SOMETIMES OVERLOOKED

There are a number of requirements relating to the movement of Over Size Over Mass (OSOM) loads that are sometimes overlooked by transport operators and/or drivers. These include checking Heavy Vehicle Travel Impacts, reducing speed when crossing bridges, and using Traffic Guidance Schemes.

Traffic Guidance Schemes

Traffic Guidance Schemes cover manoeuvres that require traffic management, including contraflow movements, facilitating movement through narrow road sections, facilitating the clearing of built-up traffic, and using crossovers, such as the Military Road crossover in Midland and the Chisholm Crescent crossover in Kewdale.

Twenty-six Traffic Guidance Schemes are available at www.mainroads.wa.gov.au

The Schemes, which cover metropolitan and regional areas were developed in consultation with industry and formalised by Main Roads for consistency.

If a Traffic Guidance Scheme is specified in permit conditions, it is essential that the Traffic Guidance Scheme is followed. If an operator needs to conduct a contraflow movement that is not covered by an existing Traffic Guidance Scheme, or if the operator believes another Traffic Guidance Scheme is required to assist with the safe movement of an OSOM load, they can have one prepared by an accredited traffic management company and submit it with their permit application.

A new Traffic Guidance Scheme can be prepared and published by Main Roads, if it is determined that it will be used regularly and benefit the wider industry.

Speed Restrictions Crossing Bridges

Various speed restrictions apply to OSOM loads crossing bridges depending on the size and mass of the load. These speed restrictions have been implemented for the safety of the bridge structures.

There is a 25 km/h speed restriction which applies to OSOM loads crossing bridges under a single trip permit. More severe speed restrictions are in place for heavier loads, which are also subject to Bridge Video Supervision. Where Bridge Video Supervision is specified on a permit for a particular bridge, the OSOM load must only cross the bridge at a maximum speed of 10 km/h, or for an OSOM vehicle consisting of a platform trailer with more than 16 axles and/or more than 12 tyres per axle, a maximum speed of 5 km/h.

Failure to comply with these speed restrictions may result in the bridge being downgraded due to structural fatigue or damage, which will mean some OSOM loads will no longer be able to cross the bridge.

Heavy Vehicle Travel Impacts

Where roadworks or events impede access for OSOM loads, these are published to enable operators and drivers to ensure their route is clear for travel. It is a requirement under an OSOM permit for drivers to check the Heavy Vehicle Travel Impacts prior to commencing their journey.

Often the Heavy Vehicle Travel Impact will specify a maximum width and/or minimum ground clearance that can be accommodated through a particular work site. There may also be a requirement for the driver or operator to contact the site supervisor prior to travelling through a particular work site, to ensure the OSOM load can be accommodated. This must be done via email or text message to ensure there is evidence that contact was made. Traffic Escort Wardens will need to see this evidence before they escort a load on a route with this requirement.

It is important that operators and drivers are familiar with all the permit operating conditions before they commence travel to ensure road safety and prevent damage to the road infrastructure. For further information please contact the Heavy Vehicle Helpdesk on 138 486 or email hvs@mainroads.wa.gov.au