Tanzhou Avenue is a major urban expressway in Xiangtan. In 2020 the main road and the service roads along a 13 km section were converted to LED street lighting using our luminaires.
The retrofit improved the brightness and uniformity of the road lighting, reduced energy use, and cut glare and light pollution compared with the old lamps.
Design notes: converting an expressway to LED
General design guidance for this type of site, not the specification of this project.
- Reuse what works. Retrofits of this kind usually keep the existing poles, arms and cables where they are in good condition, and replace the sodium heads with LED luminaires chosen for the same spacing.
- Match the class, not the old wattage. The LED wattage is chosen to meet the road’s lighting class at the existing spacing. On many roads that is well under half the old sodium wattage including ballast losses.
- Glare. Expressway drivers travel fast, so optics with good glare control (low threshold increment) matter as much as brightness.
- Savings. On a large network the energy saving pays for the luminaires within a few years, before counting fewer lamp changes.
The HPS to LED conversion chart gives typical wattage equivalents, and the LED retrofit savings calculator estimates energy, cost and payback for your own road. See our LED street lights.
