5.1 Clearance, Load, Entry and Route Restrictions
Key Takeaways
Both CLEARANCE and LOW CLEARANCE signs prohibit a vehicle higher than the stated height, including its load.
Gross load signs use actual total mass; a NO TRUCKS mass sign uses GVM of the vehicle or any unit in a combination.
A NO TRUCKS destination exception can apply where no alternative route exists or every alternative passes another such sign; it does not require a separate delivery plate.
Read what the number measures
Heavy vehicle restriction signs protect structures, road space and local routes. The same number can mean very different things on different signs. A driver should know the loaded height, vehicle and combination length, rated GVM of each unit, actual total mass and relevant axle-group masses before selecting the route. A sign is not an invitation to estimate these quantities from the appearance of the load.
Clearance signs
Both CLEARANCE and LOW CLEARANCE signs are binding under road rule 102. Do not pass if the vehicle or any connected vehicle, including its load, is higher than the stated height. There is no general rule that one type refers only to concrete while the other refers only to wires. Read the posted limit and consider the actual vehicle.
Loaded height includes cargo, raised equipment and other parts that affect the measurement. Know the height in the travel configuration, with equipment secured. Suspension movement, road camber and a sloping approach can affect practical clearance, so a marginal measured fit is not a reason to proceed blindly. Stop before the point where turning back becomes unsafe and arrange a suitable alternative if uncertain.
Actual mass signs
A GROSS LOAD LIMIT or bridge gross-mass sign refers to the actual total mass of the vehicle and any connected vehicles, including their loads. A bridge axle-group sign refers to the actual mass carried by the specified axle group. Being below GVM does not prove compliance with a bridge limit. A combination can be lawful under general mass limits and still be too heavy for a particular bridge.
For a sign showing 20 t gross mass, a combination actually weighing 21 t cannot proceed. A 19 t combination may satisfy that particular gross-mass sign, but still needs compliant axle-group mass, clearance, route access and other conditions. The rule prohibits mass more than the stated figure; do not rewrite it as a universal prohibition at exactly the figure.
NO TRUCKS signs
| Sign information | Measurement used | Key distinction |
|---|---|---|
| Mass shown | Vehicle GVM, or GVM of any unit in a combination | Rated mass, not today’s weighbridge mass |
| Length shown | Vehicle length, or overall combination length | Include the relevant full configuration |
| No mass or length shown | Truck definition | Generally a non-passenger motor vehicle above 4.5 t GVM |
The mass and length versions exclude buses from those prohibitions as the rule specifies. A mass sign can apply to a combination where just one vehicle unit exceeds the shown GVM. Emptying that unit does not reduce its rating. Do not substitute the sum of all GVMs where the rule expressly says any vehicle in the combination.
Rule 104 includes a destination exception if the destination lies beyond the sign and there is no other route to reach it, or every other route requires passing another NO TRUCKS sign. The exception is in the rule itself; it does not depend on a supplementary 'local deliveries' plate. It is not a general shortcut entitlement. If a lawful alternative route exists, inconvenience alone does not satisfy the exception.
Mandatory entry and local restrictions
A TRUCKS MUST ENTER sign requires a truck passing it to enter the indicated area. Follow the sign’s information and any lawful officer directions. A similar buses-must-enter sign applies to buses. Do not assume a light load, a familiar vehicle or an apparently closed weighbridge allows you to ignore the displayed requirement.
The handbook also discusses light-traffic roads and local restrictions. Read the actual sign and its mass or access information rather than treating 'light traffic' as a description of the current number of cars. Planning should identify these restrictions before arrival. If a route is unsuitable, find a safe place to stop and obtain a lawful route instead of reversing unexpectedly into traffic.
B-double access
An MC licence authorises the class; it does not authorise every road. B-doubles must comply with the current notice or permit, approved network, vehicle dimensions and operating conditions. Short general-access B-doubles and longer restricted-access combinations have different arrangements. Check the current NHVR notice and Tasmania’s route information for the exact combination rather than applying a memorised 25 m limit to all B-doubles.
For example, a dispatcher supplies a route used last week by a single semi-trailer. Today’s B-double may need a different authorised network. Check the first and last local access legs as well as the main highway. A permitted main route does not necessarily include the customer’s narrow side street.
Key decisions
Match each sign to its measurement, apply only the genuine exceptions and check route authority separately from driver class. Resolve uncertainty before reaching the restricted point.
Official sources
Road Rules 2019, rules 102–107 and dictionary; NHVR B-double access. Sources checked 10 October 2026.
A truck rated at 10 t GVM is empty and actually weighs 5 t. It reaches a NO TRUCKS sign showing 8 t and has a lawful alternative route. May it pass?
Yes, because actual mass is below 8 t
Yes, because every delivery is automatically exempt
No; the sign uses GVM, which exceeds 8 t
Yes, if the driver holds HC
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