Traffic Light Housing Materials & Lens Options (PC, Aluminum)

The housing and lens are the parts of a traffic light that survive the weather, the sun and the occasional impact for years. The right combination keeps the signal bright, sealed and intact; the wrong one fades, cracks or lets in water. Material and lens choices look minor on a datasheet but decide how the signal performs over its life.

This guide compares the main housing materials and lens options so you can specify the right build.

Housing materials: polycarbonate vs aluminum

Polycarbonate (PC) housings

Polycarbonate is the most common traffic signal housing material. It is lightweight, corrosion-proof, impact-resistant and does not conduct electricity. Quality PC housings are UV-stabilized to resist fading and brittleness in sunlight. For most urban installations, polycarbonate offers the best balance of durability, weight and cost.

Aluminum housings

Aluminum housings offer higher mechanical strength and better heat dissipation, and they resist deformation under high wind load or impact. They are heavier and require a protective finish against corrosion, but they suit demanding environments—large signal heads, high-wind locations or where extra rigidity is needed.

Lens options: cobweb vs clear

Cobweb (diffusing) lens

A cobweb lens has a patterned inner surface that spreads the LED light evenly across the face. It produces a uniform, fully illuminated appearance with no visible LED dots, and it reduces glare. Cobweb lenses are the most common choice where a smooth, even signal face is preferred.

Clear lens

A clear lens lets the individual LEDs be seen as distinct points of light. It can offer higher peak intensity in a defined direction and is used where a specific optical distribution is required. The trade-off is a less uniform face and more visible LED points.

Other build details that matter

• Gaskets and sealing — the lens and door gaskets determine the real IP rating, not just the housing.
• UV stabilization — prevents polycarbonate from yellowing or becoming brittle in sunlight.
• Visors / hoods — shade the lens from direct sun to maintain contrast and readability.
• Vandal resistance — relevant for accessible urban and pedestrian signals.

How to choose

Match the build to the environment and the standard. General urban intersections usually suit a UV-stabilized polycarbonate housing with a cobweb lens. Large 300–400 mm heads, high-wind or harsh sites may justify aluminum. Confirm the lens type, gasket quality and IP rating together—durability comes from the whole assembly, not one part.

Traffic light housing and lens FAQ

Is polycarbonate or aluminum better for traffic light housings?

Polycarbonate is lighter, corrosion-proof and suits most urban signals. Aluminum is stronger and more rigid, better for large heads and harsh or high-wind environments. The right choice depends on the installation.

What is a cobweb lens on a traffic light?

A cobweb lens has a patterned inner surface that diffuses LED light evenly, giving a uniform, glare-free signal face with no visible LED dots. It is the most common lens type for general signals.

Why do some traffic light housings fade or crack?

Usually because the polycarbonate was not UV-stabilized or the housing was too thin. Quality UV-stabilized housings with proper wall thickness resist fading and cracking for years in sunlight.

What keeps water out of a traffic light?

The gaskets and sealing, not just the housing. The lens and door gaskets, together with sealed cable entries, determine the real IP rating of the assembled signal.

GAOQIAO builds traffic lights with UV-stabilized polycarbonate and aluminum housings, cobweb and clear lens options, and IP-rated sealing. Browse the traffic light range, or tell us your environment for the right build.