In modern traffic management, LED traffic signals have become core infrastructure due to their energy efficiency, longevity, and high visibility. However, varying road environments and traffic volumes demand different performance characteristics from LED traffic signals. Understanding the classification methods for LED traffic signals enables purchasers and planners to make precise selections, ensuring the efficient operation of LED traffic signal systems.
traffic Light
From a core characteristics perspective, epoxy resin-encapsulated LED traffic signals are lightweight, feature lower production costs, and utilize a highly mature manufacturing process, making them widely adopted within the industry. Their key advantage lies in effectively resisting moisture and dust ingress, preventing damage to internal chips from these external factors. Additionally, they offer excellent cost-effectiveness, reducing procurement expenses while maintaining fundamental performance standards. Regarding application scenarios, they are better suited for standard LED traffic signals on ordinary urban roads, particularly in cost-sensitive areas with relatively mild environments free from extreme heat, heavy rain, or other harsh climatic conditions.
Metal epoxy resin encapsulated LED traffic signals combine the high strength of metal with the sealing properties of epoxy resin, forming their core characteristic. This characteristic endows these traffic lights with significant advantages: exceptional resistance to extreme weather conditions, ensuring stable operation under high temperatures, heavy rain, or strong winds; and superior heat dissipation, efficiently dispersing heat generated by the LED chips during operation to effectively extend their lifespan. Based on these advantages, it is suitable for use in areas with harsh climatic conditions, such as high-temperature desert regions, rainy coastal areas, and frigid northern regions, where it can operate stably over the long term in these complex environments.
The core characteristics of ceramic epoxy resin encapsulated LED traffic signal lights are outstanding thermal stability and electrical insulation. Their advantages include maintaining stable operation even in high-temperature environments without performance degradation due to excessive heat. Furthermore, they offer high electrical safety margins, effectively preventing electrical faults like short circuits and ensuring safe operation. In terms of application scenarios, it is more suitable for high-performance environments, such as LED traffic signals at highway toll stations and industrial areas, where stability and safety requirements are particularly stringent.
The core characteristics of glass-encapsulated LED traffic signals include exceptional optical transparency, allowing superior light transmission, coupled with robust physical protection against significant external impacts. Their advantages manifest in outstanding brightness and visibility, enabling drivers and pedestrians to clearly perceive signals from extended distances. Furthermore, the internal LED chips remain largely unaffected by minor physical collisions. However, these LED traffic signals carry a higher cost and have a relatively narrow application scope. They are primarily suited for scenarios demanding extremely high signal visibility, such as mountain roads prone to frequent fog or high-altitude areas with intense sunlight. In these environments, the high-visibility signals of LED traffic lights effectively ensure traffic safety.
The encapsulation type not only determines the applicable scenarios for LED traffic signals but also directly influences their core performance, primarily manifested in the following three aspects:
LED traffic signals with different encapsulation materials exhibit significant variations in aging resistance and environmental corrosion resistance. For instance, metal epoxy encapsulated LED traffic signals, protected by a metal casing, resist deformation or cracking after prolonged exposure to wind and sunlight. The failure rate of their internal chips is over 30% lower than that of standard epoxy encapsulated LED traffic signals. Glass-encapsulated LED traffic signals, while resistant to physical impact, are prone to seal failure between the glass and base when exposed to high temperatures over extended periods, necessitating regular maintenance.
traffic Light
LED chips generate heat during operation. If this heat cannot dissipate promptly, it causes the chip temperature to rise, leading to reduced brightness and a shortened lifespan of the LED traffic signal. Ceramic epoxy-encapsulated LED traffic signals possess thermal conductivity 5-8 times higher than standard epoxy-encapsulated models, rapidly transferring heat to the exterior to prevent chip overheating. Metal epoxy-encapsulated LED traffic signals achieve efficient heat dissipation through their metal casings, making them suitable for high-power applications.
From a cost perspective, standard epoxy resin-encapsulated LED traffic signals have the lowest production cost, being 50%-70% cheaper than glass-encapsulated LED traffic signals. Metal epoxy resin and ceramic epoxy resin encapsulated LED traffic signal lights, due to increased material costs and manufacturing complexity, are priced 20%-30% and 40%-50% higher respectively than standard epoxy resin encapsulated models. Therefore, when selecting LED traffic signal lights, it is essential to balance performance requirements with budget constraints to avoid unnecessary cost overruns from blindly pursuing high-end encapsulation.
LED traffic signal lights feature diverse light-emitting surface shapes, including circular, square, rectangular, surface-emitting tubes, side-emitting tubes, and external micro-tubes. Different shapes suit varied installation scenarios and signaling requirements. Among these, circular light-emitting surface LED traffic signal lights are the most widely used type. Their sizes are categorized by diameter into multiple specifications with corresponding industry standard labels, as follows:
In addition to circular designs, square and rectangular LED traffic signals with flat light-emitting surfaces are typically used in multi-phase configurations (such as combination signals incorporating left-turn, straight-through, and right-turn indicators). This design enables clearer delineation of signal zones for different phases. LED traffic signals with flat light-emitting tubes enhance signal coverage through their larger luminous area, making them suitable for intersections with high pedestrian traffic. LED traffic signals with side-emitting tubes and externally mounted micro-tubes are primarily used in specialized scenarios (e.g., tunnel LED traffic signals, temporary construction zone LED traffic signals).
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Conventional LED traffic signals feature a half-value angle of 20°-45°, concentrating luminous intensity primarily in the forward direction with reduced side visibility. These lights are typically employed as indicator lights—such as power indicators or fault warning lights—or installed in highly visible locations (e.g., directly above intersections) to ensure drivers can clearly perceive signals while traveling straight ahead.
Diffuse-type LED traffic signals feature a half-value angle of 45°–90°, with some products exceeding 90°. Their light-emitting surfaces incorporate scattering diluents that disperse light over a wider angle, providing excellent side visibility. This type is the mainstream choice for vehicular traffic signals, particularly suited for installation on the sides of intersections. It ensures drivers in different lanes (e.g., left-turn lane, straight-through lane) can clearly recognize the signal, preventing misjudgments due to viewing angle issues.
High-directional LED traffic lights feature a narrow half-value angle, typically ranging from 5° to 20°, with some products even below 5°. Employing a pointed epoxy resin encapsulation or metal reflector cavity design without scattering diluents, light is highly concentrated directly forward.
The advantage of this type lies in maintaining high brightness at long distances. It is suitable for miniature LED traffic signals (e.g., warning lights in temporary construction zones) or installation on roads with extended sight lines (e.g., straight highway sections), ensuring drivers can perceive the signal from hundreds of meters away.
Standard-brightness LED traffic signals emit less than 10mcd. Their core features include low energy consumption, preventing waste, and producing soft light that avoids glare for drivers. These are best suited for low-visibility environments like tunnels or well-lit residential roads at night, where ambient light is dim and high brightness isn’t required for clear signal recognition. They also serve basic signaling needs in low-traffic areas such as rural roads or internal industrial park routes.
High-brightness LED traffic signals feature luminance levels between 10-100mcd. Their core characteristic is moderate brightness, ensuring clear visibility during daytime conditions while preventing nighttime glare for drivers. This achieves an optimal balance between energy efficiency and visibility. They are primarily used in standard LED traffic signals for ordinary urban roads, such as secondary roads and branch road intersections. These signals accommodate typical urban traffic flow requirements, ensuring accurate signal recognition under varying time periods and lighting conditions.
Featuring an intensity exceeding 100mcd, ultra-high brightness LED traffic signal lights deliver exceptional luminosity and interference resistance. They maintain clear visibility even in adverse conditions like heavy fog, torrential rain, or snowstorms, as well as under direct intense sunlight. Their primary applications include high-traffic areas such as urban thoroughfares and intersections, where complex traffic conditions demand rapid signal recognition. Additionally, high-speed zones like highways and expressways, along with regions prone to severe weather, require these LED traffic signals to ensure drivers can quickly identify signals from long distances or in challenging environments, thereby reducing accident risks.
traffic Light
Visibility is a core functional requirement for LED traffic signals. Studies indicate that under identical conditions, LED traffic signals are perceived as 40%-60% brighter than traditional incandescent signals. For instance, ultra-high-brightness LED signals offer 2-3 times greater visibility than incandescent signals in foggy conditions, granting drivers more reaction time and effectively reducing rear-end collision rates.
The energy consumption of LED traffic signals is positively correlated with luminous intensity. Selecting appropriate LED signal brightness levels can reduce energy consumption while maintaining visibility. For instance, on well-lit roads at night, standard-brightness LEDs (<10mcd) consume only 1/5 to 1/3 of the energy used by high-brightness LEDs. Long-term deployment significantly lowers operational costs for urban LED traffic signal systems, aligning with sustainable development principles.
Standard current LED traffic signals operate within a range of 10mA to several tens of mA. Their core characteristic is higher current draw, enabling sufficient brightness to ensure clear visibility of signals in complex traffic environments. However, higher current also results in relatively higher energy consumption. In terms of application scenarios, they are more suitable for locations with heavy traffic flow and high brightness requirements, such as intersections on urban main roads where dense vehicle traffic necessitates rapid and accurate recognition of LED traffic signal indications. Another example is highway toll stations, where vehicles travel at high speeds, and sufficient brightness allows drivers to promptly detect LED traffic signal instructions for toll lanes.
Low-current LED traffic signals operate at less than 2mA, with low current consumption being their defining feature. This results in extremely low energy usage, effectively conserving power while still meeting basic signal indication requirements. Their primary applications are in energy-efficient scenarios, such as smart LED traffic signals. These often integrate sensors for automatic brightness adjustment, where the low-current characteristic enhances compatibility with intelligent control systems, further reducing energy consumption. Additionally, low-current LEDs are ideal for low-traffic areas like rural roads and parking lot entrances/exits. With minimal traffic flow and lower brightness requirements, these lights meet operational needs while reducing energy consumption and maintenance costs.
For LED traffic signals installed at busy intersections operating 24/7, standard-current models require robust thermal management to prevent premature failure from sustained high-load operation. Conversely, for LED traffic signals installed in remote areas with low traffic volume, selecting low-current models not only reduces energy consumption but also lowers maintenance frequency (as low-current LEDs generate less heat and exhibit lower failure rates).
When selecting LED traffic signals in practice, balance brightness and energy efficiency based on specific requirements. For instance, in intelligent transportation systems, low-current LED traffic signals can be paired with ambient light sensors. During daytime with strong illumination, current can be appropriately increased to enhance brightness, while reducing current at night with low light to conserve energy. This “on-demand adjustment” approach balances signal performance and energy savings.
The four distinguishing factors—encapsulation, light-emitting surface, luminous intensity, and operating current—are interrelated and collectively determine LED traffic signal performance. Selecting appropriate LED traffic signals based on specific scenarios ensures traffic safety while reducing costs. With future technological advancements, LED traffic signals will become smarter, offering greater support for traffic management.
