Truck Axle Load Limits South Africa: Complete Reference Guide

Understanding truck axle load limits South Africa is non-negotiable for fleet managers and transport operators. Overloading damages roads, risks lives, and triggers heavy fines and impoundment under the National Road Traffic Act. This guide gives you the exact limits, the legal framework, consignor liability rules, and practical steps to stay compliant—so you can bookmark it and run your fleet within the law.

Legal framework: National Road Traffic Act (NRTA)

South African truck weight and axle limits are set by the National Road Traffic Act 93 of 1996 (NRTA) and its regulations. The Act empowers the Minister of Transport to prescribe maximum masses for vehicles and combinations, and the current limits are given in the National Road Traffic Regulations (as amended).

Key points:

Steering axle, single axle, tandem axle, and tridem axle limits are prescribed per axle group.
Gross Vehicle Mass (GVM) and Gross Combination Mass (GCM) limits apply to the whole vehicle or combination.
A bridge formula constrains the combined mass of axle groups and the distance between them to protect road structures.
Overloading is an offence; penalties include progressive fines, demerit points, and impoundment.
Consignors and consignees have specific duties under Regulations 330A–330D (load declarations, payload capacity, records). Failure to comply can shift liability for overloading to the consignor.

Compliance is the responsibility of the operator, driver, and—where applicable—the consignor. Ignorance of the limits is not a defence.

Axle load limits: quick reference tables

The following limits apply to vehicles and vehicle combinations on South African roads under the NRTA framework. All masses are in kilograms (kg).

Steering axle limit

Axle type	Maximum mass	Notes
Steering axle	7 700 kg	Single axle that steers the vehicle. Often the front axle on rigid trucks and tractors.

The steering axle limit is lower than other single axles to protect steering geometry and tyre wear. Exceeding it also increases the risk of steering failure.

Single axle (non-steering)

Axle type	Maximum mass	Notes
Single axle	9 000 kg	Any single axle that is not the steering axle.

This applies to a single axle not forming part of a tandem or tridem group. Drive axles on a rigid truck (when only one rear axle) typically fall under this limit.

Tandem axle limit

Axle type	Maximum mass	Notes
Tandem axle	18 000 kg	Two axles in a group (e.g. dual rear axles on a rigid truck, or drive axles on a tractor).

The 18 000 kg is the total mass on the tandem group, not per axle. Spacing and configuration must still satisfy the bridge formula (see below).

Tridem axle limit

Axle type	Maximum mass	Notes
Tridem axle	24 000 kg	Three axles in a group (e.g. on a trailer or certain rigid vehicles).

Again, 24 000 kg is the total for the group. Tridem axles are common on semi-trailers and some tipper configurations.

Summary: axle group limits

Axle group	Maximum mass (kg)
Steering axle	7 700
Single axle	9 000
Tandem axle	18 000
Tridem axle	24 000

These are the building blocks. The actual permissible GVM or GCM for your vehicle depends on its configuration and the bridge formula.

GVM and vehicle configuration

Gross Vehicle Mass (GVM) is the maximum allowed mass of a vehicle (including load) as specified by the manufacturer or as determined by regulation. Gross Combination Mass (GCM) is the maximum allowed mass of a vehicle combination (e.g. tractor + semi-trailer).

Permissible GVM is the lower of:

The manufacturer’s plated GVM, and
The sum of the permissible masses of all axle groups, limited by the bridge formula.

Typical GVM examples by configuration (illustrative; always confirm with your vehicle’s plating and current regulations):

Configuration	Typical max GVM (kg)	Notes
2-axle rigid (steering + single)	16 700	7 700 + 9 000
3-axle rigid (steering + tandem)	25 700	7 700 + 18 000
4-axle rigid (steering + tridem)	31 700	7 700 + 24 000
5-axle articulated (tractor + semi)	56 000 (GCM)	Common for freight; bridge formula applies

Actual limits for your vehicle must be read from the certificate of fitness and manufacturer’s plate. Never assume a higher GVM than plated or legally derived.

The bridge formula

The bridge formula limits the total mass that may be carried on two or more consecutive axle groups based on the distance between the first and last axle in the group. It prevents excessive loading on bridges and culverts.

In simplified terms:

The allowed mass on a set of axles depends on the distance (L) between the first and last axle in that set.
Formula (conceptually): W = k × L, where W is total mass and L is in metres. The constant and exact form are set in the regulations.
If the mass on the axles exceeds what the formula allows for that distance, the vehicle is overloaded even if each individual axle group is within its 7 700 / 9 000 / 18 000 / 24 000 kg limit.

When planning loads and axle spacing (e.g. sliding tandems on trailers), operators must ensure both:

No single axle group exceeds its limit (steering 7 700, single 9 000, tandem 18 000, tridem 24 000), and
The combined mass and axle spacing comply with the bridge formula.

Weighbridge staff and traffic authorities use the formula to check compliance. Fleet and load planners should use it when allocating payload to avoid overloads at the weighbridge.

Overloading penalties: fines and impoundment

Overloading is taken seriously. Penalties under the NRTA and related enforcement (including AARTO) include:

Progressive fines: Fines increase with the degree of overload (e.g. percentage over the limit). Serious overloads attract much higher amounts.
Demerit points: Operators and/or drivers can receive demerit points under the AARTO system, affecting operator cards and licences.
Vehicle impoundment: Vehicles may be impounded until the overload is corrected and fines paid. This causes downtime, extra cost, and contractual risk.

Staying within axle and GVM/GCM limits is the only way to avoid these outcomes. Pre-trip weighing and consignor load declarations (see below) are essential.

Consignor and consignee liability (Regulations 330A–330D)

Regulations 330A to 330D place clear duties on consignors (and in some cases consignees). If they are not followed, liability for overloading can shift to the consignor.

Obtain payload capacity in writing

The consignor must obtain written information from the operator on the payload capacity of the vehicle (or combination) that will be used. Payload capacity means the mass of cargo the vehicle can legally carry (GVM minus tare, or equivalent for combinations). Relying on verbal or informal information is not sufficient.

Maintain load declaration records

The consignor must keep load declaration records. These typically include:

Identity of the operator and vehicle
Payload capacity provided by the operator
Description and declared mass of the load
Date and consignment details

Records must be kept for the period required by regulation and produced on request. Without them, the consignor cannot demonstrate due diligence.

Fuel allowance (up to 1 000 litres in tare)

When calculating payload capacity, fuel in the vehicle’s tanks may be treated as part of the tare mass (unladen mass) up to a limit of 1 000 litres. This gives operators a consistent way to account for fuel without reducing payload. Fuel above 1 000 litres is typically counted as part of the load for weight compliance.

Liability shifts to consignor

If the consignor:

Fails to obtain written payload capacity from the operator, or
Loads the vehicle in excess of that capacity, or
Fails to keep or provide load declaration records when required,

then the consignor can be held liable for the overloading offence, in addition to or instead of the operator/driver. Consignors must therefore have processes to get payload in writing, declare loads accurately, and keep records.

Operators should support consignors by providing clear, written payload capacity and cooperating on load declarations. Thwala TMS helps by capturing payload capacity and generating load declarations so both parties stay compliant.

Weighbridge procedures and requirements

Weighbridges are used to enforce axle and GVM limits. Drivers and operators should:

Stop when directed at a weighbridge. Failing to stop or attempting to evade is an offence.
Position the vehicle as instructed so that each axle or axle group is weighed correctly (static or in-motion weighing, as per the facility).
Produce documents when required (e.g. licence, operator documents, load documentation).
Comply with instructions if found overloaded (e.g. off-load excess, move to a safe area). Resisting or refusing can lead to impoundment and additional charges.

Weighbridge staff may weigh the whole vehicle, axle groups, or both. Overload on any axle group or on GVM/GCM makes the vehicle non-compliant. Knowing your vehicle’s tare and axle distribution helps you avoid overloads before you reach the weighbridge.

Practical tips: how to avoid overloading

Get written payload capacity for every vehicle/combination you use and share it with consignors. Update it when configuration or equipment changes.
Manage tare weight: Know the actual tare of each vehicle (including fuel up to 1 000 L, driver, tools, and equipment). Extra bodywork or equipment reduces payload.
Use load declarations: For every consignment, declare the load type and mass. Match the declared mass to the payload capacity and ensure the consignor has written capacity and keeps records.
Pre-trip weighing: Where possible, weigh loads before dispatch (own weighbridge or a nearby facility). Check axle distribution, not only total mass. Adjust load placement or use a different vehicle if needed.
Train drivers and planners: Ensure they know the axle limits, bridge formula basics, and consignor rules. Include weighbridge procedure in driver briefings.
Use TMS to support compliance: A transport management system can store payload capacity, generate load declarations, and flag trips that exceed capacity—reducing the risk of overloading and consignor liability. Thwala helps fleet managers track payload, manage declarations, and avoid overload-related fines and impoundment.

How TMS software helps with axle and load compliance

Transport management systems (TMS) can support compliance with truck axle load limits and consignor regulations in several ways:

Payload capacity and vehicle master data: Store GVM, tare, and legal payload per vehicle/combination. Use this for written payload capacity to consignors and for load planning.
Load declarations: Generate and store load declarations (load type, mass, consignor, vehicle) linked to each trip. This supports Reg 330A–D record-keeping for consignors and operators.
Overloading alerts: When planning a trip, compare declared or planned load mass to payload capacity and flag overloads before dispatch. Some systems integrate with weighbridge or onboard weight data for real-time checks.
Reporting and audits: Produce reports on payload utilisation, load declarations, and compliance for internal audits and RTMS or authority checks. RTMS certification often requires evidence of load and overloading controls; a TMS provides a clear audit trail.

Investing in a TMS that supports payload, declarations, and overloading prevention is a practical step toward staying within truck axle load limits South Africa and meeting consignor liability requirements.

Summary table: truck axle load limits South Africa

Item	Limit or requirement
Steering axle	7 700 kg
Single axle	9 000 kg
Tandem axle	18 000 kg
Tridem axle	24 000 kg
GVM / GCM	As plated and bridge formula; typical 5-axle GCM 56 000 kg
Bridge formula	Combined axle mass limited by distance between first and last axle in group
Consignor	Obtain written payload capacity; keep load declaration records; up to 1 000 L fuel in tare
Overloading	Fines, demerits, impoundment; consignor liable if Reg 330A–D not followed

Frequently asked questions

What is the steering axle limit in South Africa?

The maximum mass on the steering axle is 7 700 kg under the National Road Traffic Act and regulations. This is the single axle that steers the vehicle (typically the front axle). It is lower than the 9 000 kg allowed on other single axles to protect steering and tyres.

What happens if my truck is overloaded at a weighbridge?

You can face progressive fines (higher for greater overload), demerit points under AARTO, and vehicle impoundment until the overload is corrected and any fines are paid. The vehicle may not be driven until it is within legal limits. Consignors can also be liable if they did not obtain written payload capacity or keep load declaration records as required by Regulations 330A–330D.

Who is liable for overloading: operator or consignor?

Both can be liable. The operator and driver are responsible for ensuring the vehicle is not overloaded. The consignor has duties under Reg 330A–330D: obtain written payload capacity from the operator, ensure the load does not exceed that capacity, and keep load declaration records. If the consignor fails these duties and the vehicle is overloaded, liability can shift to the consignor. Operators should provide written payload capacity and support load declarations to protect both parties.

How much fuel can I count as tare weight?

Up to 1 000 litres of fuel in the vehicle’s tanks may be included in the tare mass when calculating payload capacity. Fuel above 1 000 litres is typically counted as part of the load for compliance with weight limits. This is set out in the NRTA regulations and affects how much cargo the vehicle can legally carry.

Bookmark this page for quick reference to truck axle load limits South Africa, the bridge formula, consignor rules, and overloading penalties. For RTMS and broader compliance, see our RTMS certification South Africa guide. To manage payload, load declarations, and overloading risk across your fleet, explore Thwala—logistics and transport management software built for South African operators.