Introduction
A signal can be suspended over a road by a cantilever pole (single pole with horizontal arm) or by span wire (two poles with a tensioned cable). The choice depends on road width, aesthetic preference, and budget. This guide compares the two.
Cantilever (Signal Arm) Pole
A cantilever pole is a single pole with a horizontal arm extending over the lane. The signal head hangs from the arm tip. Pros: clean look, only one foundation, easy maintenance. Cons: heavier pole, larger foundation, higher cost per pole.
Ask GAOQIAO to confirm the available cantilever-pole height, arm length and design documentation for the project. Urban or suburban location alone does not determine suitability; check loads, clearances and foundation requirements.
Span Wire
A span wire installation uses two poles (one on each side of the road) with a tensioned steel cable between them. The signal heads hang from the cable. Pros: works on very wide roads, lower cost per pole. Cons: two foundations to build, the cable can sag over time, the look is dated.
Span-wire supports may be considered where road width, structural feasibility and local streetscape requirements favour them. Compare them with cantilever alternatives using the actual span, loads, foundations and maintenance requirements, rather than selecting solely by lane count.
Decision Matrix
| Factor | Cantilever | Span wire |
|---|---|---|
| Lane count up to 4 per direction | Preferred | Acceptable |
| Lane count 5+ per direction | Review alternative support arrangements through the approved structural design. | Preferred |
| Aesthetic | Modern, clean | Dated, visible cables |
| Foundation cost | One foundation | Two foundations |
| Pole cost | Higher per pole | Lower per pole |
| Maintenance | Easier (one pole to inspect) | Harder (cable tensioning) |
Featured Products
GAOQIAO supplies both signal arm poles and vertical poles for span wire use. See the pole selection guide.
Conclusion
Compare cantilever and span-wire supports using road geometry, structural loads, clearances, utilities, maintenance access and local design requirements. Lane count or appearance alone is not sufficient to choose the support. Send GAOQIAO the approved site requirements to confirm available products and any engineering information needed for evaluation.
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Frequently Asked Questions
Can I add a second arm to an existing cantilever pole?
Only after a structural assessment confirms the additional load is permitted. Check the original approved pole and foundation drawings and any documented allowance for future equipment. Ask GAOQIAO to confirm the scope of the supplied design information; do not assume expansion capacity is included.
How long does a span wire last?
Specify inspection and maintenance for the actual cable-supported signal system, including cable tension, anchors, poles and corrosion. Service life depends on materials, loads, exposure and condition assessments; do not assume universal cable and pole lives of 15-20 and 25-30 years.
Which is more expensive?
Compare complete installed costs, including all poles, foundations, support hardware, cabling and maintenance access. Neither cantilever nor span-wire support is inherently cheaper; the required number and size of supports depend on the approved layout and loads.
Relevant GAOQIAO products
These public GAOQIAO catalogue pages are related to the guide. Open them for the representative description, then confirm the latest drawing and configuration before ordering.
- Traffic signal controllersWired and solar controllers with 6, 22, 44 and 56 output options.
- LED traffic signal heads200mm, 300mm and 400mm signal heads; confirm the selected model and applicable project requirements.
- Signal polesVertical, signal arm and double-arm poles; confirm suitability for the approved site design.
- Spare parts and accessoriesSpare LED modules, lenses, visors, surge arrestors and anchor bolts.
Related buyer resources
- Traffic Signal Controller Cabinet Guide
- Traffic Light Wiring Diagram Guide
- Traffic Light IP Ratings Guide
- Traffic Signal Head Specification Guide
- Solar Traffic Signal Site Survey
- Contact GAOQIAO
Discuss cantilever or span-wire traffic signal support requirements
Related guides: poles and installation
Continue with these related resources for your traffic signal project.