Overhangs and Load Projections: The Abnormality Most Often Missed

Overhang and projection are two different things, and mixing them up is how a legal truck becomes an illegal one.

• Overhang is the vehicle’s own body extending beyond its axles.
• Projection is the cargo extending beyond the vehicle.

Different regulations, different limits — and they interact, in a way that catches people out. A truck with a generous rear overhang gets a far smaller allowable projection than one without. This is the abnormality most often missed, because it can be created by nothing more than loading a long item slightly further back.

Overhang — the vehicle

Regulation 226 governs this, and the front limit depends on the shape of the cab.

Vehicle	Maximum front overhang
Front of vehicle to the driver’s seat backrest is less than 1,7 m (a cab-forward truck)	the lesser of 60% of the wheelbase, or 6,2 m less half the wheelbase
That distance is more than 1,7 m (a bonneted truck)	the lesser of 60% of the wheelbase, or 5,8 m less half the wheelbase
Semi-trailer	1,8 m

Which of the two formulas binds depends on your wheelbase, and it switches:

• 4 m wheelbase — 60% gives 2,40 m; 6,2 − 2,0 gives 4,20 m. The 60% rule binds: 2,40 m.
• 6 m wheelbase — 60% gives 3,60 m; 6,2 − 3,0 gives 3,20 m. The subtraction binds: 3,20 m.

Work both and take the smaller. Assuming the 60% rule always applies will over-state what you are allowed on a longer wheelbase.

Rear overhang

Measured from the rearmost axle, Regulation 226 limits rear overhang on a goods vehicle to 60% of the wheelbase. Under permit, a load-carrying abnormal vehicle may go to 2 m or 70% of the wheelbase, whichever is the greater — but that allowance is explicitly “subject to the restriction on load projection” below.

Projection — the cargo

Front

Regulation 227 limits load projection to 300 mm beyond the front end of the vehicle. Under permit, no abnormal load may project more than 1,0 m beyond the front of the drawing vehicle.

Rear — three numbers, and they do different jobs

Number	What it means	Source
300 mm	Beyond this, the projection must be indicated with warning devices	Regulation 229
1,8 m	The legal maximum projection	Regulation 227
1,8 m	Beyond this, a rear own escort should be provided	TRH 11 §2.6.2.2

300 mm is not the limit — it is the point at which you must flag it. Plenty of operators treat the flagging threshold as the legal maximum, or the legal maximum as the flagging threshold. They are 1,5 m apart.

And the projection is not the only test: Regulation 227 also requires the combined length of load and vehicle to stay inside the ordinary length limits — 12,5 m for a single vehicle, 18,5 m articulated, 22,0 m for other combinations. A legal projection on an already-long combination can still put you over.

Under permit: how far a rear projection may go

Here is the interaction, and it is the point of this page. Where the vehicle’s rear overhang exceeds 50% of the wheelbase, the cargo’s rear projection may not exceed 0,5 m. Full stop.

Only where rear overhang is under 50% of the wheelbase do you get the fuller allowance, measured two ways at once:

Wheelbase	(a) beyond the centre of the rearmost axle unit	(b) beyond the rear end of the vehicle
3 m	3,9 m	2,6 m
4 m	4,6 m	2,9 m
5 m	5,2 m	3,2 m
6 m	6,0 m	3,5 m
7 m	6,0 m	3,7 m
8 m	6,0 m	4,0 m
9 m	6,0 m	4,3 m
10 m and more	6,0 m	4,5 m

Note that column (a) stops rising at 6,0 m from a 6 m wheelbase onward, while column (b) keeps climbing. Past that point it is the distance beyond the rear of the vehicle that governs.

The height allowance

Where the load sits 2,5 m or more above the road surface, the projection may be increased by 20% or 750 mm, whichever is the lesser. The logic is visibility and clearance: a projection at head height is a different hazard from one over a following car’s bonnet.

Working it out

1. Measure your wheelbase and your rear overhang from the rearmost axle.
2. Is rear overhang more than 50% of wheelbase? If yes, your rear projection ceiling is 0,5 m and nothing in the table helps you.
3. If no, read both columns of Table 2.6 for your wheelbase and satisfy both.
4. Check the combined length against 12,5 / 18,5 / 22,0 m.
5. Flag anything over 300 mm; expect a rear escort past 1,8 m.
6. Then try loading it further forward, which is free, before applying for anything.

Questions people ask

What is the difference between overhang and load projection?
Overhang is the vehicle’s own body extending beyond its axles, governed by Regulation 226. Projection is the cargo extending beyond the vehicle, governed by Regulations 227 and 229. They have different limits and they interact.

How far can a load stick out the back of a truck in South Africa?
Legally, no more than 1,8 m — and anything beyond 300 mm must be indicated with warning devices. The combined length of load and vehicle must also stay inside the normal length limits. Longer projections need a permit, and past 1,8 m a rear own escort should be provided.

Why is my allowable projection only 0,5 m?
Because your vehicle’s rear overhang exceeds 50% of its wheelbase. In that case TRH 11 caps the rear load projection at 0,5 m regardless of what the wheelbase table would otherwise allow.

Does a high load get more projection?
Yes. Where the load is 2,5 m or more above the road surface, the projection may be increased by 20% or 750 mm, whichever is the lesser.

What is the maximum front projection?
300 mm beyond the front of the vehicle legally. Under permit, no abnormal load may project more than 1,0 m beyond the front of the drawing vehicle.

Where this comes from

• Overhang limits — TRH 11 §2.5, reproducing Regulation 226.
• Projection limits — TRH 11 §2.6, reproducing Regulations 227 and 229.
• The permit table and its riders — TRH 11 Table 2.6 and §2.6.2.2.
• The worked wheelbase examples — our own arithmetic from the two formulas, shown so you can check it.

Measure your own vehicle. These are the rules; the numbers that matter are the ones on your truck with your load on it, and a permit office can attach conditions beyond them.

Next

• Abnormal, bulk and special loads — the hub
• Escorts, flags and warning lights — what the permit requires once you are abnormal
• Truck configurations — where the length limits come from
• Kweli Load Exchange — loads matched to your truck and corridor