Modern urban lighting is undergoing a transformation from meeting universal standards to implementing scenario adaptation and refined design. Its core goal is to achieve precise lighting design from “illumination” to “empowerment” based on regional functions, traffic flow, user needs, and spatial cultural attributes. Based on current national standards and industry practices, this paper systematically analyzes lighting design strategies in different regions.
1. Graded Lighting Standard System: Differentiated design based on road functional levels
According to the “Urban Road Lighting Design Standard” (CJJ 45-2015), the fundamental principle of graded road lighting design is to set differentiated evaluation indicators for each lighting based on the traffic function level undertaken, balancing traffic safety, visual comfort, and energy consumption control.
- Standard basis: CJJ 45-2015 is a fundamental national standard in this field, clearly specifying the standard lighting values for motor vehicle lanes and sidewalks.
- Technical Parameter Analysis:
- Expressways and main roads: corresponding to Class I lighting in the standard. Its standard brightness value is 1.5–2.0 cd/m², maintaining an average standard illuminance of 20–30 lx. To ensure longitudinal continuity and reduce interfering light, there are clear requirements for longitudinal uniformity (≥0.7), and truncated or semi-intercepted luminaires must be used.
- Secondary roads and branch roads: corresponding to Class II and Class III lighting, respectively. Its illuminance, brightness, and glare limits are correspondingly reduced. The lighting standards for branch roads do not impose mandatory requirements for environmental ratio (SR), reflecting a comprehensive consideration of the functions and costs of different levels of roads.
- Sidewalks and Non-Motor Vehicle Lanes: The evaluation criteria have shifted from “brightness” to “illuminance” of motor vehicle lanes, emphasizing the importance of vertical illuminance in enhancing pedestrian facial recognition and a sense of safety, marking a shift in design philosophy toward “people-oriented.” Some local guidelines (such as Yiyang City plans) further provide detailed suggestions for different levels of road color temperature, such as first-class lighting recommended at 1900-3500K, which can serve as a supplementary reference for refined design.
Core logic: The road lighting grading system optimizes visual comfort and energy efficiency through quantified technical indicators, ensuring the baseline of traffic safety.
2. Lighting strategies for key nodes and special functional areas
For traffic nodes and specific functional areas, lighting design needs to break through the standard limitations of conventional road sections and implement more targeted design strategies.
- Intersections and crosswalks (crosswalks): For safety, the standard lighting values are usually 1.5 times or more than those of the connected roads. For example, the standard value for maintaining an average illuminance at the intersection area of the main road is 30/50 lx. Special attention must be paid to vertical illumination in the design to enhance pedestrian visibility and strictly control glare interference for drivers.
- Bus stops: It is advisable to install independent lighting to eliminate shadows caused by large vehicles parking, ensuring safe visibility in waiting areas, pick-up and drop-off areas, and around vehicles.
- Parks and recreational trails: Lighting objectives balance basic safety guidance with creating an ambient environment. Recommended illuminance values are usually low (e.g., 3-5 lx), and color temperatures are mostly warm (2700-3500K) to create a quiet and elegant nighttime environment. The installation height of the fixtures is usually controlled between 3.5-5m to reduce light disturbance to the natural ecosystem and avoid excessive lighting.
- Historic and Cultural Districts: Lighting design should harmonize with its appearance. The design and style of the lighting fixtures should be integrated into the local cultural context; The light color should be static and gentle; Fixtures should have a high color rendering index (Ra≥80) to accurately present building materials and colors. Its fundamental purpose is to protect and convey the historical and cultural memory of a place through the language of light and shadow.
Design Focus: Lighting design for special areas deepens from “meeting standards” to “solving problems.” Its success depends on precise identification and response to the safety, function, and cultural needs of specific spaces.
3. Collaborative strategies for functional lighting and atmosphere creation
In commercial areas, mixed-function zones, and similar scenarios, lighting design needs to collaboratively address the contradictory need between basic safety functions and the creation of a commercial atmosphere.
- Layered design approach: An effective strategy is to use layered lighting. Uses white light with high color rendering and suitable color temperature as the base lighting, meeting basic functions such as safety and recognition; At the same time, localized, controllable dynamic light or decorative colored lights are used to embellish the business. Some city guidelines (such as Guangzhou Nansha New Area) quantify the usage ratio and form of such decorative colored lights, providing a management basis for design.
- Dialectical control of glare: In scenes such as commercial pedestrian streets, limited and controlled glare can be used as a visual stimulus to create a bustling and lively commercial atmosphere. The key prerequisite is to ensure there are no direct harmful glare interferences along the main pedestrian paths and safe zones. This “controlled visual stimulation” sharply contrasts with the functional areas that pursue absolute glare.
- Integration with green and low-carbon requirements: While pursuing ambiance, it is essential to follow the macro requirements of green lighting, strictly controlling core energy consumption indicators such as illuminance and power density. By promoting efficient LED light sources and adopting intelligent control systems to achieve time-segmented dimming, it is possible to achieve business goals while maintaining energy consumption control.
The Way of Balance: Advanced lighting design lies in achieving dynamic balance across multiple objectives. Through grading, zoning, and intelligent control, the relationship between “brightness” and “darkness,” “stillness” and “movement,” and “function” and “atmosphere” is finely regulated, ultimately achieving multiple goals of safety, comfort, energy saving, and commercial value.
4. Conclusion:
The core evolutionary path of modern urban lighting design can be summarized into three levels: first, following a scientifically quantified grading standard system; Second, precise scenario adaptation is made for key nodes and special functional areas; Ultimately, a creative balance of function and atmosphere is achieved in the complex functional area. This process requires designers to have a deep understanding of national standards, master advanced technologies, and possess the ability to transform abstract norms into concrete spatial solutions.