Why Are Laser Lights Installed on Highways?

[MacJasmine]

Highway roads are straight with few fixed reference points, leading to monotonous driving actions and a single line of sight for drivers. Prolonged driving under such conditions can easily cause drowsiness. This is more pronounced in summer, as the daytime heat drains physical energy. Freight drivers often undertake long-distance trips at night, making them prone to fatigue driving, which has become a key illegal activity targeted for prevention and enforcement by highway traffic authorities. Installing laser lights can alter the monotonous driving environment and mitigate visual fatigue through changes in light. After multiple rounds of concentrated discussions, highway traffic police have placed laser lights on relatively straight sections of road where fatigue driving is more likely to occur. The lasers are adjusted to ensure sufficient brightness while also providing a certain visual impact. The laser lights come in two forms: continuous and strobe, with a range of 2 kilometers.

[DiThomas]

Actually, those laser lights on highways are primarily for safety purposes. Have you seen the green light strips projected above the entrance of highway tunnels? That kind of laser beam can penetrate two to three kilometers of fog, acting like a guiding line at night. Long-distance drivers know how terrifying it is when entering a tunnel and suddenly facing complete darkness—these lasers pre-illuminate the walls and road edges, preventing pupils from abruptly contracting. Two years ago, I spoke with a Sichuan highway maintenance team, and they mentioned that tunnels equipped with lasers saw a 40% reduction in rear-end collisions. They even pointed out the sensors on the laser devices: when fog density exceeds a certain level, the brightness automatically increases, which is much smarter than simply using yellow fog lights.

[CharlieMarie]

Last time I was driving at night in a heavy rainstorm, I suddenly saw purple laser beams piercing through the rain curtain and instantly realized this section of the road was equipped with laser lights. After consulting with a road engineer, I learned that during heavy rain or fog, regular lighting suffers from severe scattering, but laser beams at specific wavelengths act like 'light knives' cutting through the rain and fog. The most practical function is indicating curves—when straight laser beams encounter a curve, they refract and distort noticeably, allowing drivers to detect changes in road direction up to 500 meters in advance. Some road sections even project lasers onto retaining walls to create dashed light bands, simulating lane markings, which is especially helpful for long-haul drivers fighting drowsiness.

[IsaacFitz]

A truly knowledgeable maintenance worker will tell you that this type of lighting saves both money and hassle. Last year in the Qinling Tunnel, workers were seen replacing lamps and complaining about high-pressure sodium lights constantly burning out. After switching to laser lights, they saved 80% on electricity. The key advantage is the extended maintenance cycle—ordinary fixtures require disassembly three times a year, while laser equipment only needs servicing once every five years. The latest models can even sync with weather stations, automatically switching to high-penetration purple light in heavy fog and shifting to energy-efficient green mode on sunny days.