Street roadway lighting plays a crucial role in ensuring safety on busy streets and highways, where visibility is essential. Proper lighting can reduce night crashes by approximately 30%, making roads safer for drivers, riders, and pedestrians. When it comes to road lighting luminaires, there are three types: cut-off, semi cut-off, and non cut-off. In this article, we will explore the differences between these three types and their respective advantages.
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Cut-off Luminaires: The Best Glare Control
Cut-off luminaires have a specific light distribution that offers the best glare control. The angle between the maximum light intensity direction of the lamp and the downward vertical axis is between 0° and 65°. The maximum allowable value of the light intensity in the 90° angle and 80° angle direction is 10cd/1000lm and 30cd/1000lm, respectively. Regardless of the size of the luminous flux, the maximum light intensity in the 90° angle direction does not exceed 1000cd.
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The advantage of cut-off luminaires is that they effectively control glare by controlling the lateral extension of light, resulting in the darkening of the area around the road. Glare is barely perceptible, and high road surface and brightness uniformity can be achieved. Cut-off luminaires are suitable for main roads and expressways.
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Reference light distribution of Cut-off luminaire:
- 2X2 LED LENS T2M Cut-off
- 2x3 LED LENS T2M Cut-off
- 2X4 T2M Cut-off
Semi Cut-off Luminaires: Balanced Glare Control
Semi cut-off luminaires have an angle between the direction of the maximum light intensity of the lamp and the downward vertical axis between 0° and 75°. The maximum allowable value of the light intensity in the direction of 90° and 80° is 50cd/1000lm and 100cd/1000lm, respectively. Similar to cut-off luminaires, the maximum light intensity in the 90° angle direction does not exceed 1000cd, regardless of the luminous flux.
Semi cut-off luminaires offer a good balance between glare control and visibility. There is some glare, but it is at a tolerable level. These luminaires are suitable for secondary trunk roads and branch roads.
Reference light distribution of semi cut-off luminaire:
- 2x2 LED LENS MEW TypeIV-Very Short
- 2X2 LED LENS street light IES TypeII-M
Non Cut-off Luminaires: Versatile Lighting Solution
Non cut-off luminaires have no specific limit on the maximum light intensity direction of the lamp. The maximum light intensity in the 90° angle direction does not exceed 1000cd, regardless of the luminous flux. These luminaires are suitable for bicycle lanes and sidewalks.
Reference light distribution of non cut-off luminaire:
- 2x2 LED LENS 5050 LEDs T2M-No backlight diagram
- 2x2 LED LENS 5050 LEDs T2M-With backlight diagram
Summary of the Three Types of Luminaires
| Type of Luminaire | Imax Direction | The max allowable value of the light intensity emitted in the specified angle direction | 90° | 80° |
|---|---|---|---|---|
| Cut-off Luminaire | 0°~65° | 10cd/1000lm | 30cd/1000lm | |
| Semi Cut-off Luminaire | 0°~75° | 50cd/1000lm | 100cd/1000lm | |
| Non-Cut-off Luminaire | - | 10cd | - |
Glare control: Lens Cut-off luminaire Semi Cut-off luminaire Non Cut-off luminaire
Power Efficiency: Lens Cut-off luminaire Semi Cut-off luminaire Non Cut-off luminaire
If you're looking for lighting solutions for different road types, understanding the difference between cut-off, semi cut-off, and non cut-off luminaires is essential. Each type offers its own advantages in terms of glare control and power efficiency, catering to specific road requirements.
Frequently Asked Questions
Q: Which type of luminaire is suitable for main roads and expressways?
A: Cut-off luminaires are the best choice for main roads and expressways due to their excellent glare control and high brightness uniformity.
Q: What are semi cut-off luminaires suitable for?
A: Semi cut-off luminaires strike a balance between glare control and visibility, making them ideal for secondary trunk roads and branch roads.
Q: Where are non-cut-off luminaires commonly used?
A: Non-cut-off luminaires are versatile and can be used in various applications, such as bicycle lanes and sidewalks.
Q: Which type of luminaire offers the best glare control?
A: Cut-off luminaires provide the best glare control among the three types.
Q: Which type of luminaire has the highest power efficiency?
A: Cut-off luminaires have the highest power efficiency, followed by semi cut-off luminaires and non cut-off luminaires.
Remember, when choosing the right luminaire for your road lighting needs, consider factors such as glare control, visibility, and power efficiency to ensure safety and optimal illumination.
