Heavy Vehicle Road Signs, Access Restrictions, and Oversize/Overmass Permits

Heavy vehicle road signs you must recognise

The Victorian road network uses a specific set of regulatory and warning signs aimed at heavy vehicles. The HR knowledge test asks you to identify what each sign requires or prohibits, so recognise the symbol and the legal effect.

No Trucks

The No Trucks sign is a red-ring prohibition sign showing a truck symbol, sometimes with a mass figure (e.g., "No Trucks Over 12 t"). It prohibits trucks — usually vehicles with GVM over 4.5 t, or over the mass shown — from entering the road, lane, or area. If no mass is shown, the default prohibition applies to vehicles over 4.5 t GVM. Local councils and VicRoads use No Trucks signs on residential streets and bridges that cannot safely carry heavy vehicle loads. Exemptions exist for local-delivery trucks that need access to premises within the prohibited area, but only where a sign allows it (typically text such as "Except Local Trucks" or a time-based exemption).

Trucks Must Enter

The Trucks Must Enter sign (a white panel with a black truck symbol and an arrow) directs trucks to take a specific action — typically to enter a specified side road, slip lane, or rest area. Where the sign is placed before a junction it obliges trucks to use the indicated route; ignoring it is an offence. Closely related are Trucks Use Low Gear signs on descents and Trucks Use Left Lane signs on multi-lane roads.

Load limit signs

Load limit signs restrict vehicles above a stated laden mass or axle mass. Examples include:

• No Vehicles Over 12 t GVM — applies to the actual laden mass at the moment of crossing the bridge or roadway, not the vehicle's plated GVM. A 22 t GVM truck that is only loaded to 11 t may pass a 12 t limit sign.
• Axle Group Limit signs — restrict the mass carried by a single axle group (e.g., "No Axle Group Over 6 t").
• Bridge Load Limit signs — show a gross mass limit for the bridge; some signs list different limits for different vehicle configurations.

If you are unsure of your laden mass, treat the sign as if it applies to you and find an alternative route or a weighbridge. Bridge overload causes structural damage and is a serious offence.

Bus Give Way and Bus Lane

Under Victorian road rules (Road Safety Road Rules 2017):

• Bus Give Way: in a built-up area where the speed limit is 60 km/h or less, you must give way to a bus that is displaying a 'Give Way to Buses' sign and is indicating to re-enter traffic from a bus stop, bus zone, or the side of the road. This rule applies to all drivers including heavy vehicle drivers; failing to give way is an offence.
• Bus Lane: a lane marked with a 'Bus Lane' sign and a white diamond or 'B' lane marking is reserved for buses (and sometimes bicycles) during the times shown. Trucks must not travel or stop in a bus lane during its hours of operation unless signage permits.
• Bus Zone / Taxi Zone signs: trucks must not stop in these zones, even briefly, outside permitted hours.

Truck lane and route restrictions

On multi-lane roads, signs may require trucks to use a specific lane (commonly Trucks Use Left Lane on freeways) or prohibit trucks from the right lane. The Victorian default on freeways with a 100 km/h or higher limit is that vehicles over 4.5 t GVM must not travel in the right lane unless overtaking, passing, or avoiding an obstruction. Local signs override this default.

Oversize and overmass permits

A vehicle or load that exceeds any general-access dimension (4.3 m height, 2.5 m width, 12.5 m length) or any general mass limit becomes an overdimensional (OD) or overmass (OM) load. Operating such a vehicle on a public road without a permit is an offence under the HVNL.

Permits are issued by:

• The National Heavy Vehicle Regulator (NHVR) for travel that crosses state borders or uses the national network (most Victorian permits for OS/OM loads are NHVR permits under the Class 1 or Class 3 permit framework).
• VicRoads for some state-only access, bridge, and route approvals where the national framework does not apply.

A typical OS/OM permit specifies:

• The vehicle and load description (dimensions, mass, axle count).
• The approved route — you may not deviate from the mapped route.
• Travel times — often restricted to daylight hours, and may exclude weekends, public holidays, or peak periods.
• Pilot/escort vehicle requirements (see below).
• Signs and flags — "OVERSIZE" signs front and rear, corner flags on projections, rotating amber warning lights.
• Speed limits — often below the posted limit for stability and braking.

OD routes, low-clearance signs, and automatic clearance gauges

Approved routes for OS/OM loads are called OD routes. The NHVR publishes route maps; VicRoads supplements with state-level approvals. Drivers must plan the entire route from origin to destination before departure, including any turning paths, bridge mass ratings, and overhead clearances.

Low-clearance signs are warning signs showing the available height under a structure (e.g., "Low Clearance 4.0 m"). The figure on the sign is the measured clearance, typically updated by the road authority after resurfacing. Drivers must compare the loaded vehicle height against the sign. If the loaded height is at or above the posted clearance, do not proceed — find an alternative route.

Automatic clearance gauges are physical height-checking frames (sometimes laser-based) installed before low bridges, tunnels, and some carparks. They detect an overheight vehicle and trigger warning signs, flashing lights, or barriers. If a gauge triggers as you approach, stop and reassess — do not proceed under the structure. Automatic gauges reduce but do not eliminate bridge strikes; the driver remains responsible for verifying loaded height.

Pilot vehicles

Oversize loads above certain thresholds must be accompanied by pilot vehicles (also called escort vehicles). Pilot vehicles:

• Travel ahead of (and/or behind) the OS/OM load.
• Display roof-mounted 'OVERSIZE' signs and amber flashing/warning lights.
• Warn oncoming traffic, control traffic at narrow points, and communicate with the OS/OM driver by radio.
• Help the OS/OM driver navigate tight turns and confirm overhead clearances.

The number of pilot vehicles required scales with the load dimensions and route. A load only slightly over width may need one pilot; a very wide or long load may need two pilots plus a police escort. The OS/OM permit states the requirement; you may not travel with fewer pilots than the permit specifies.

Practical pre-departure checks for access

Before driving an oversize/overmass load, confirm:

1. The permit is current and carried in the vehicle.
2. The approved route matches the planned trip, with no deviations.
3. The vehicle's loaded dimensions and mass match the permit (an OS/OM permit is invalid if the actual load differs from what was approved).
4. Pilot vehicles (if required) are present, correctly signed, and able to communicate by radio.
5. OVERSIZE signs, flags, and amber warning lights are fitted and working.
6. Bridge heights and load limits on the route have been checked against the loaded vehicle.
7. Travel-time restrictions in the permit are observed (no travel outside approved hours).

Failure to comply with any permit condition is an offence and can void insurance and trigger Chain of Responsibility liability for the operator, scheduler, and consignor.