After more than a decade in the foreign trade business-starting with high-pressure sodium lamps and now focusing on complete LED street lighting solutions-one of the questions I hear most often from overseas buyers is: "Can your lights meet the local road lighting standards?" Many clients are not familiar with how Chinese urban roads are classified or what the exact illuminance and uniformity values are for each grade. Today I'll clearly explain the three main levels-arterial roads (including expressways), secondary roads, and local/branch roads-based on the Standard for Lighting Design of Urban Road (CJJ 45 series). This should help you communicate more effectively during quoting and proposal discussions.
How Road Grades Align with Lighting Levels
Urban roads are functionally divided into three grades for motor-vehicle lighting: expressways and arterial roads, secondary roads, and local (branch) roads. Lighting standards follow the same classification. Key evaluation indicators include average road-surface illuminance (or average luminance), illuminance uniformity (or overall luminance uniformity and longitudinal uniformity), glare limitation, and surround ratio. The standard provides both a higher value and a lower value. Medium and small cities, or roads with well-developed traffic control and separation facilities, usually adopt the lower value. City centers, commercial areas, ceremonial roads, or high-traffic sections take the higher value.
Average illuminance figures are based on asphalt pavement; for concrete pavement, the values may be reduced by about 30%. All figures are maintained values, so a maintenance factor must be applied in design.
Illuminance and Uniformity Requirements for Arterial Roads (Including Expressways)
Arterial roads and expressways belong to the highest lighting class. Maintained average illuminance is 20/30 lx, corresponding to average luminance of 1.5/2.0 cd/m². Minimum illuminance uniformity UE is 0.4, overall luminance uniformity Uo is 0.4, and longitudinal uniformity UL is 0.7. Maximum initial threshold increment TI is 10%, and minimum surround ratio SR is 0.5.
In practice, arterial roads carry higher speeds and heavier traffic volumes. Drivers need clearer pavement information and longer sight distances. Insufficient uniformity creates bright and dark patches that cause visual fatigue and can lead to misjudgment. On several arterial road projects we supplied to Southeast Asia and the Middle East, clients initially focused only on illuminance. Later field measurements showed uniformity falling short, resulting in costly rework. We then insisted on LED luminaires with better light distribution and strictly calculated pole spacing and mounting height, which finally delivered stable compliance.
Illuminance and Uniformity Requirements for Secondary Roads
Secondary roads form the intermediate link between arterial roads and local roads. Maintained average illuminance is 15/20 lx, with average luminance of 1.0/1.5 cd/m². Minimum illuminance uniformity UE is 0.4, overall luminance uniformity Uo is 0.4, and longitudinal uniformity UL is 0.5. Maximum initial TI remains 10%, and minimum SR is 0.5.
Traffic volume on secondary roads is moderate, yet basic safety and visual comfort are still required. Many secondary roads are bordered by shops or residential areas, so lighting must serve both motor vehicles and the adjacent pedestrian environment. In trade negotiations, clients often ask whether power can be reduced further. Power reduction alone is not enough; uniformity must be recalculated at the same time. Dropping power while letting uniformity fall below 0.3 produces a noticeably poorer result and raises the risk of later complaints.
Illuminance and Uniformity Requirements for Local (Branch) Roads
Local roads are the lowest motor-vehicle grade. Maintained average illuminance is 8/10 lx, corresponding to average luminance of 0.5/0.75 cd/m². Minimum illuminance uniformity UE is 0.3, and overall luminance uniformity Uo is 0.4; longitudinal uniformity is generally not mandated. Maximum initial TI is relaxed to 15%.
Speeds and volumes are lower, so the standard is less stringent. However, many local roads lead directly into residential areas, where pedestrians' sense of security remains important. Some projects push illuminance close to the lower limit to save cost, only to generate more resident complaints about shadows at night. We recommend keeping uniformity as high as practical once the minimum illuminance is met-especially easy with LED sources whose light distribution can be tightly controlled.
Practical Experience and Points to Watch
Standards are fixed; site conditions are not. Pavement material, pole height, luminaire light distribution, and maintenance cycle all affect final performance. Export projects also have to account for local climate, voltage fluctuation, and installation habits. On several African and South American jobs, local crews paid little attention to tilt angle, causing uniformity to drop sharply. We later locked mounting angles and pole-spacing ranges into the drawings and installation manuals and supplied a simple acceptance checklist; rework rates fell noticeably.
Note also that intersection areas require higher illuminance-arterial-to-arterial intersections may reach 30/50 lx. Sidewalks and non-motorized paths follow separate criteria and cannot simply adopt motor-vehicle values.
After years in this business, I have found that explaining the standards clearly is more valuable than simply offering the lowest price. Once a client understands the requirements, they are far more likely to recognize the real value and long-term reliability of a properly engineered solution.
If you are working on an overseas road-lighting project or need a scheme adjusted to local regulations, feel free to send the road grade, pavement type, and approximate pole spacing. We can provide illuminance calculations and luminaire recommendations tailored to your conditions and help you avoid unnecessary detours.
