TW-series signs are South Africa’s standard for temporary road traffic control signs. Required under SADC-RTSM Chapter 13, they include the TW336 road works triangle, danger plates, R1.5 Stop/Go boards, TW702 worker flags and TW904 end-of-restriction signs. Non-compliance is a contractor liability issue.
Every road construction and maintenance site in South Africa requires temporary road traffic control signs to warn road users, protect workers, and define the limits of the works zone. These signs follow the TW-series — the South African standard for temporary traffic management signage.
This guide explains what TW-series signs are, which ones you need on site, and how to stay compliant with SADC-RTSM Chapter 13.
What Are TW-Series Signs?
TW stands for Temporary Warning. The TW-series is a set of standardised road signs used specifically for road construction, maintenance, and repair operations. They fall under Chapter 13 of the SADC Road Traffic Signs Manual (SADC-RTSM), the regional standard that governs road signs across Southern Africa, including South Africa.
TW-series signs are distinct from permanent road signs:
- Portable and temporary — designed to be set up and removed as work zones move
- High-visibility — fluorescent orange or yellow with reflective sheeting
- Standardised in size — available in 600mm, 900mm and 1200mm panel sizes
- Reflective — Class 1 (standard) and Class 2 (high-intensity prismatic) sheeting options
TW-Series Quick Reference
| Sign Code | Name | Purpose | When Required | Available Sizes |
|---|---|---|---|---|
| TW336 | Road Works Ahead Triangle | Advance warning to approaching traffic | Every road construction or maintenance site | 600mm, 900mm, 1200mm |
| Danger Plate | Works Zone Boundary | Marks entry and exit of the hazard zone | Every works zone — start and end positions | 600mm, 900mm, 1200mm |
| TW702 | Worker Present Flag | Warns of workers on or near the carriageway | Whenever workers are physically on the road | Standard |
| R1.5 | Stop/Go Board | Manual alternating traffic control | When works zone reduces road to single-lane alternating flow | 600mm diameter |
| TW411 | Boom Sign | Visual definition of zone edge | Attached to barriers and cones at zone boundary | Standard |
| TW904 | End of Restrictions | Marks end of temporary works zone | At the far end of every works zone with advance warning signs | Standard |
The Key TW-Series Signs
TW336 — Road Works Ahead Triangle
This is the primary advance warning sign for road construction. A large fluorescent orange equilateral triangle with a road works symbol, the TW336 is placed in the advance warning sequence before the works zone — typically 150m to 300m from the start of the taper, depending on road speed limit.
The TW336 is required on every road construction site as the first warning to approaching road users.
Danger Plate — Works Zone Boundary Marker
A plain fluorescent yellow diamond with no symbol or text, the danger plate marks the first and last sign positions in a works zone sequence. It defines the entry and exit boundaries of the hazard area.
The danger plate is different from the TW336 — it marks where the zone starts and ends, not what is ahead. Both are required on every works zone. Using one in place of the other is a SADC-RTSM non-compliance finding.
For a detailed breakdown of the danger plate, see our guide: Danger Plate Road Signs in South Africa: What They Are and When to Use Them
TW702 — Worker Present Flag Sign
A square sign with a fluorescent flag symbol, TW702 warns road users that workers are present on or near the road surface. It is placed within the works zone, after the initial warning sequence.
TW702 is required whenever workers are physically present on the carriageway.
R1.5 — Stop/Go Board
The R1.5 Stop/Go board is used when traffic flow through a works zone requires manual alternating control. One traffic controller holds the board showing STOP to approaching traffic while the opposite queue moves; then the board reverses to show GO.
R1.5 boards are required whenever a works zone reduces the road to single-lane alternating traffic under manual control. Traffic controllers must wear high-visibility vests.
TW411 — Boom Sign
Boom signs attach to temporary barriers or cones at the edge of the works zone, providing additional visual definition of the zone boundary. They help drivers track the edge of the lane through the works.
TW904 — End of Restrictions
Placed at the end of the works zone, TW904 indicates to road users that the temporary restrictions are complete and normal road conditions resume. Every works zone that uses advance warning signs must also have an end-of-restrictions sign at the other end.
Sign Sizes and Reflectivity Requirements
SADC-RTSM Chapter 13 specifies sign sizes based on road speed limit:
| Speed Limit | Minimum TW336 Triangle Size |
|---|---|
| Up to 60 km/h | 600mm |
| 60–100 km/h | 900mm |
| Over 100 km/h | 1200mm |
Reflective sheeting classes:
- Class 1 (standard reflective): Suitable for lower-speed roads with adequate ambient lighting
- Class 2 (high-intensity prismatic): Required for high-speed roads, national roads, and night works
Contractor Liability and Compliance
Under South African law, the contractor or employer responsible for the works zone is liable for the correct placement and condition of all temporary road signs. A missing or incorrectly placed sign that contributes to an accident can result in civil liability, COID claims, and potential prosecution under the National Road Traffic Act.
Failing an SANRAL, provincial roads department, or municipal inspection for missing TW-series signs typically results in a stop-work order until compliance is restored.
Frequently Asked Questions
Do I need TW-series signs for a small pothole repair?▼
Yes. Any road maintenance work that affects traffic flow or places workers near the carriageway requires temporary road signs under SADC-RTSM Chapter 13, regardless of the job size. The minimum requirement is a TW336 advance warning sign and appropriate worker protection signage.
What is the difference between a danger plate and a TW336?▼
The TW336 is a fluorescent orange triangle placed in advance of the works zone — it warns drivers of what is ahead. The danger plate is a plain fluorescent yellow diamond placed at the start and end of the works zone itself — it marks the boundary. Both are required on every works zone and they are not interchangeable.
What size TW336 sign do I need for an 80 km/h road?▼
For an 80 km/h road, you need a minimum 900mm TW336 triangle. The 900mm size applies to all roads in the 60–100 km/h speed range. Using a 600mm sign on an 80 km/h road is a SADC-RTSM non-compliance finding.
Does a Stop/Go board operator need any certification?▼
The operator must be trained in traffic control procedures and must wear a Class 2 or Class 3 hi-vis vest. While there is no single nationally mandated certification, SANRAL and most municipal road authorities require a traffic accommodation certificate. The operator must be positioned to face oncoming traffic clearly.
What is the difference between Class 1 and Class 2 reflective sheeting?▼
Class 1 (standard reflective) is suitable for lower-speed roads with adequate lighting. Class 2 (high-intensity prismatic reflective) is required for national roads, high-speed roads, and any night works. Class 2 provides significantly greater retroreflectivity — signs remain clearly visible from a much greater distance at night and in low-light conditions.
Who is liable if a TW-series sign is missing or incorrectly placed?▼
The contractor or employer responsible for the works zone carries liability under the National Road Traffic Act. A missing sign that contributes to an accident can result in civil liability and potential prosecution. Both SANRAL and municipal roads departments issue stop-work orders for non-compliant sign setups.
Can I use the same TW-series signs on multiple sites at the same time?▼
No. Each active works zone must have its own complete set of signs in place for the duration of the work. Moving signs from one site to another while work is ongoing at both sites leaves one site unprotected and non-compliant. Dimple Safety can supply complete sets for multiple concurrent sites — contact us for a multi-site quote.
Where to Buy TW-Series Signs in South Africa
Dimple Safety stocks the full TW-series range from our Booysens, Johannesburg warehouse:
- TW336 triangles — 600mm, 900mm, 1200mm — Class 1 and Class 2 reflective
- Danger plates — 600mm, 900mm, 1200mm
- R1.5 Stop/Go boards
- TW702 worker present signs
- TW411 boom signs
- TW904 end of restrictions signs
All signs are manufactured to SADC-RTSM Chapter 13 specification. Collect same day from Booysens or request a quote for site delivery.
📞 011 493 3000 | 🌐 dimplesafety.co.za | 📍 22 Fraser Street, KAJ Park, Unit 8, Booysens, Johannesburg
