5.2 Load Projections, Overhang Limits & Red Flag/Lamp Warning Standards
Key Takeaways
- Regulation 226(1)(b)(i) limits the front overhang of a rigid heavy vehicle to 60% of its wheelbase, measured from the centre-line of the front axle.
- Regulation 226(2)(c) limits the rear overhang of an ordinary goods vehicle to 60% of the wheelbase; the 70% figure applies only to buses, motor homes and refuse, street-cleaning or sewage vehicles.
- Regulation 227 caps goods projections at 300 mm beyond the front of the vehicle, 1,8 metres beyond the rear, and 1,25 metres (1,3 metres for a goods vehicle of 12 000 kg GVM or more) either side of the longitudinal centre-line.
- Regulation 229(2) requires a red flag of at least 300 mm by 300 mm once a load projects more than 300 mm past the rear, with a flag on each side unless the projection is less than 600 mm wide.
- At night, or whenever persons and vehicles are not visible at 150 metres, a projecting load must show red devices to the rear, white devices to the front and yellow devices along its sides.
5.2 Load Projections, Overhang Limits & Red Flag/Lamp Warning Standards
When loading commercial freight, cargo must often be accommodated on vehicle bodies with varying dimensions. However, allowing cargo to extend too far forward, rearward, or sideways compromises vehicle handling, creates dangerous blind spots, and poses lethal collision risks to surrounding traffic. The National Road Traffic Regulations, 2000 address these risks through three separate regulations that the K53 examination treats as one topic: Regulation 226 (overhang of the vehicle), Regulation 227 (how far goods may project), and Regulation 229 (the flags, lamps and reflectors that warn other road users).
Keeping the three apart is the whole skill. Overhang is about the vehicle; projection is about the goods; warning devices are about making the projection visible.
1. Legal Overhang Limitations (Regulation 226)
Vehicle overhang refers to the portion of the vehicle chassis, body, or carried cargo that extends beyond the vehicle's axles. Overhang limits are expressed as a proportion of the vehicle's wheelbase.
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| WHEELBASE & OVERHANG ANATOMY |
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| |
| |<--- FRONT OVERHANG --->|<------------ WHEELBASE ------------>|<--- REAR OVERHANG --->|
| | (Max 60% of WB) | (Front Axle to Rear Drive Axle) | (Max 60% of WB) |
| |
| [====FRONT====] [=====CAB=====] [====BODY====] |
| O===============================O=============================| |
| FRONT AXLE REAR AXLE REAR OF LOAD |
| |
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The Wheelbase Definition
To calculate permissible overhang, a driver must know the vehicle's wheelbase:
- For a two-axle rigid truck, the wheelbase is the longitudinal distance measured from the centre-line of the front axle to the centre-line of the rear axle.
- For a multi-axle rigid truck equipped with a tandem rear axle unit, the wheelbase is measured from the centre-line of the front axle to the midpoint between the two rear axles.
Front Overhang Limits
Under Regulation 226(1)(b)(i), a vehicle other than a semi-trailer or a single-axle trailer may not have a front overhang exceeding 60% of the wheelbase. Front overhang is measured horizontally along the vehicle's longitudinal axis from the centre-line of the front axle forward to the foremost point of the vehicle. (A semi-trailer is handled separately under Regulation 226(1)(a), which caps its front overhang at 1,8 metres.)
Rear Overhang Limits: The 60% Rule — and the 70% Exception That Is Not Yours
This is the single most misquoted figure in heavy-vehicle prep material, and the K53 examination rewards candidates who know which number belongs to which vehicle.
| Vehicle Type | Maximum Rear Overhang | Regulation |
|---|---|---|
| Goods vehicle (ordinary rigid truck — your Code 10 vehicle) | 60% of the wheelbase | 226(2)(c) |
| Refuse-compactor, street-cleaning or sewage-disposal vehicle | 70% of the wheelbase | 226(2)(a) |
| Bus or motor home | 70% of the wheelbase | 226(2)(a) |
| Trailer with one axle, one axle unit, or two axles less than 1,2 m apart | 50% of the body length | 226(2)(b) |
[!WARNING] The 70% Trap. A distractor answer of "70% of the wheelbase" is placed in exam questions precisely because it is a real figure — it just belongs to refuse trucks, buses and motor homes, not to a general freight truck. For the rigid goods vehicle you are licensed to drive on a Code 3 learner's licence, the answer is 60%. Note also that there is no absolute metre cap on rear overhang in Regulation 226; the limit is purely proportional to the wheelbase.
Rear overhang is measured from the centre-line of the rear axle (or centre of the tandem axle unit) to the rearmost point of the vehicle bodywork.
2. Worked Overhang Calculation Scenarios
Scenario A: Short Wheelbase Delivery Truck
- Vehicle Specifications: A 4-tonne Code C1 delivery truck has a measured wheelbase of 4,0 metres.
- Front Overhang Calculation:
- Rear Overhang Calculation:
- Result: A body or load that reaches 2,8 metres behind the rear axle centre-line puts this truck 400 mm over the legal rear overhang, even though the vehicle looks perfectly ordinary from the kerb.
Scenario B: Long Wheelbase Rigid Freight Chassis
- Vehicle Specifications: A heavy rigid Code C freight chassis has a wheelbase of 5,2 metres.
- Front Overhang Calculation:
- Rear Overhang Calculation:
- The Second Test: Overhang is not the only constraint. Regulation 227(2) requires that the vehicle plus any projection still fits inside the overall length permitted by Regulation 221 — 12,5 metres for a rigid goods vehicle. A long-wheelbase chassis can satisfy the 60% overhang calculation and still be illegal because the total length has crept past 12,5 metres.
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| THE TWO-TEST SEQUENCE |
| |
| TEST 1 (Reg 226): Rear overhang <= 60% of wheelbase |
| TEST 2 (Reg 221 via Reg 227(2)): Overall length incl. projection <= 12,5 m |
| |
| A load is legal only when BOTH tests pass. |
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3. How Far Goods May Project (Regulation 227)
Regulation 226 governs the vehicle. Regulation 227 governs the goods carried on it, and it sets three hard distances that are examination favourites.
| Direction of Projection | Statutory Maximum | Regulation |
|---|---|---|
| Beyond the front end of the vehicle | 300 millimetres | 227(1)(a)(ii) |
| Beyond the rear end of the vehicle | 1,8 metres | 227(1)(a)(iii) |
| Sideways from the longitudinal centre-line — wide bus or goods vehicle of 12 000 kg GVM or more | 1,3 metres | 227(1)(a)(i)(aa) |
| Sideways from the longitudinal centre-line — any other vehicle | 1,25 metres | 227(1)(a)(i)(bb) |
| Bracket beyond the widest part of the vehicle | 150 millimetres | 227(1)(b)(ii) |
Two points repay careful reading:
- Sideways projection is measured from the centre-line, not from the body. A goods vehicle of 12 000 kg GVM or more may carry goods reaching 1,3 metres either side of its longitudinal centre-line — which is exactly half of the 2,6 metre overall width that Regulation 223 allows such a vehicle. In other words, the load may fill the legal width but never exceed it. Side mirrors and direction indicators are expressly excluded from the measurement.
- The front projection allowance is tiny. Only 300 mm of goods may reach past the front end of the vehicle, and Regulation 227(1)(b)(i) adds that the front overhang together with the projection may not exceed the 60% front-overhang figure from Regulation 226(1)(b).
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| PROJECTION LIMITS FOR A CODE 10 TRUCK |
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| |
| 300 mm max 1,8 m max |
| |<-->| |<----------->| |
| [====##=================== TRUCK BODY ====================##=========] |
| |
| Sideways: 1,3 m either side of the centre-line (GVM >= 12 000 kg) |
| 1,25 m either side of the centre-line (any other vehicle) |
| ... and the overall width (Reg 223) may still never exceed 2,5 m / 2,6 m. |
| |
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4. Warning Devices for Projecting Loads (Regulation 229)
When a load projects past the physical extremities of a motor vehicle, other road users cannot readily perceive the hazard, especially at dusk, in fog, or at night. Regulation 229 sets the two thresholds at which warning devices become compulsory: 150 mm to the side and 300 mm to the rear.
Threshold 1 — Load Projecting More Than 150 mm Beyond the Side (Regulation 229(1))
- By day: flags of red cloth, not less than 300 mm by 300 mm, suspended by two adjacent corners transversely to the direction of travel, from the front and the rear of the projection.
- By night (between sunset and sunrise, or whenever persons and vehicles are not clearly visible at 150 metres): a white retro-reflector or white lamp at the outer edge of the front of the load, and a red retro-reflector or red lamp at the outer edge of the rear of the load.
Threshold 2 — Load Projecting More Than 300 mm Beyond the Rear (Regulation 229(2))
- By day: a red flag or red cloth of not less than 300 mm by 300 mm hung at the end of the projection to show its length, plus similar flags hung parallel to the direction of travel on both sides of the end of the projection to show its width. Where the projection is less than 600 mm wide, a single flag at the end is sufficient.
- By night or in poor visibility: red retro-reflectors or red lamps fitted on the end of the projection to indicate its width (one is sufficient where the projection is less than 600 mm wide), and yellow retro-reflectors or yellow lamps fitted on both sides of the projection at its end to indicate its length.
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| REGULATION 229 PROJECTING LOAD WARNING STANDARDS |
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| |
| TRIGGER 1: load projects > 150 mm BEYOND THE SIDE |
| Day : red flags >= 300 x 300 mm at the front AND rear of the projection |
| Night : WHITE reflector/lamp at the front outer edge |
| RED reflector/lamp at the rear outer edge |
| |
| TRIGGER 2: load projects > 300 mm BEYOND THE REAR |
| Day : red flag/cloth >= 300 x 300 mm at the end (length) |
| plus a flag each side (width) - ONE flag only if width < 600 mm |
| Night : RED reflectors/lamps on the end (width) |
| YELLOW reflectors/lamps on both sides at the end (length) |
| |
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The 600 mm Rule
The figure that distinguishes "one warning device" from "two" is 600 millimetres, not 400. Where the rear projection is less than 600 mm wide, one flag by day and one red reflector or lamp by night is enough, because a narrow projection such as a single length of pipe or a steel girder has effectively no width to mark out. At 600 mm and wider, both extremities must be marked so that a following driver can judge the true width of the obstruction closing on them.
[!IMPORTANT] Critical Legal Distinction: Red flags do the work during daylight. Between sunset and sunrise — and at any other time when persons and vehicles on the road are not clearly discernible at 150 metres — flags are not enough and the prescribed reflectors or lamps must be fitted. Driving after dark with projecting steel pipes marked only with red cloth is an offence under Regulation 229 and will earn a discontinuation notice at the next weighbridge or traffic checkpoint.
Overhang and Projection Standards Matrix
| Element | Statutory Limit | Warning Standard Required | Governing Regulation |
|---|---|---|---|
| Front overhang (vehicle) | Maximum 60% of wheelbase | — | Regulation 226(1)(b)(i) |
| Rear overhang (goods vehicle) | Maximum 60% of wheelbase | — | Regulation 226(2)(c) |
| Rear overhang (bus, motor home, refuse vehicle) | Maximum 70% of wheelbase | — | Regulation 226(2)(a) |
| Goods projecting past the front | Maximum 300 mm | White reflector/lamp at night | Regulations 227(1)(a)(ii), 229(1) |
| Goods projecting past the rear | Maximum 1,8 metres | Red flag by day / red and yellow lamps by night once the projection exceeds 300 mm | Regulations 227(1)(a)(iii), 229(2) |
| Goods projecting sideways | 1,3 m from centre-line (GVM >= 12 000 kg); 1,25 m otherwise | Flags/lamps once the projection exceeds 150 mm beyond the side | Regulations 227(1)(a)(i), 229(1) |
| Overall width including load | 2,5 m, or 2,6 m for a goods vehicle of 12 000 kg GVM or more | — | Regulation 223 |
| Overall length including projection | 12,5 m for a rigid goods vehicle | — | Regulations 221(f), 227(2) |
| Warning flag size | Not less than 300 mm x 300 mm red cloth | Two flags unless the projection is under 600 mm wide | Regulation 229 |
| Night visibility standard | Devices effective at 150 metres | Red to the rear, white to the front, yellow along the sides | Regulation 229 |
A rigid goods vehicle used for general freight has a wheelbase of 5,0 metres. Under Regulation 226 of the National Road Traffic Regulations, what is the maximum permissible rear overhang?
A load on a goods vehicle projects 900 mm beyond the rear of the vehicle and is 750 mm wide. The driver will be travelling during daylight. What does Regulation 229 require?
How far beyond the rear end of the vehicle may goods carried on a heavy goods vehicle lawfully project?