i think they used foggy street light. instead of normal light.for safety reason maybe hot day cold night condensation built up on the mekhong river. thats why its not very bright at night in normal condition.but when its a foggy day or night you could see the road abit better.
Fluorescent ຫລອດໄຟເຫົ່ລານີ້ ທຳງານໂດຍ ກາຣ ສົ່ງຜ່ານກະແສຜ່ານຫລອດ ທີ່ເຕັມໄປດ້ວຍ ອາຣ໌ກອນ(argon) ກ໊າຊ ແລະສານ mercury ນີ້ຜະລິດ ລັງສີອັດຕຣາໄວ ໂອເລຕ that bombards the phosphorous coating causing it to emit light (ເບິ່ງ: \"ວິທີ fluorescents ທຳງານ\") ຊີວິຕຫລອດຍາວນານ - 10,000 ຖຶງ 20,000 ຊົ່ວໂມງ ຫລອດຟລູອອເຣນອກຈາກນີ້ຢັງມີປະສິດທິພາບຫລາຍ, ກາຣຜລິຕຄວາມຮ້ອນນ້ອຍຫລາຍ. ຄວາມເຂົ້າໃຈ ທັງຫມົດເປັນຫລອດ Fluorescent ເປັນກາງ ຫລຶເຢັນໃນລັກຊະນະສີ ຄວາມຈຣິງທີ່ວ່າໃນອດີຕ \"ສີຂາວ\" ຫລອດໄຟນີອອນ ເປັນມາດຕຣາຖານໃຊ້ໃນອຸດສາຫາກໍາ. color appearance (4200K) and poor CRI rating (62). This is simply no longer the case. Regarding color, a wide variety of fluorescent lamps (T12, T8, T5, etc.), using rare-earth tri-phosphor technology, offer superior color rendition (as high as 95) and a wide range of color temperature choices (from 2700K to 5000K and higher).
LED (Light Emitting Diodes) Light Emitting Diodes (LED) ເປັນຫລອດໄຟໂດຍບໍ່ມີໄຍ without a filament, ທີ່ຕ່ຳໃນການໃຊ້ພລັງງານ ແລະມີຊ່ວງຊີວິດທີ່ຍາວນານ LEDs ເປັນຫລອດໄຟທີ່ເພິ່ງເລີ້ມຕົ້ນສ້າງຂື້ນໃຫມ່ໆ ເທກໂນໂລຢີໃຫ່ມ ລ້າສຸດ ແຕ່ໂຊກຮ້າຍທີ່ພວກເຂົາ ບໍ່ມີ the output (lumen) needed to completely replace incandescent, and other type, bulbs just yet.