What does turning on hazard lights in a traffic jam on the highway mean?

[OAiden]

Turning on hazard lights in a traffic jam on the highway is a way to signal danger to vehicles behind. Traffic regulations state: In case of a breakdown or accident on the highway, hazard warning lights must be turned on, and at night, width markers and tail lights should also be activated. When the light switch is turned to the first position, the small front and rear lights that illuminate are the width markers, indicating the vehicle's width to alert other drivers. Hazard lights, also known as emergency lights, cause both sides' small lights to flash simultaneously when activated, warning passing vehicles to drive safely. When to use hazard lights: Hazard lights are typically used in foggy or heavy rain conditions, when the vehicle breaks down, or in emergency situations. If you see a vehicle driving slowly, moving in an S-shape, or with hazard lights on, it may indicate that the vehicle is in need of assistance or signaling for help. Therefore, when driving, it's important to be attentive to other drivers on the road. In other words, flashing hazard lights serve as an alarm signal, indicating that the vehicle has a minor driving issue, such as inability to accelerate or maintain speed, alerting following vehicles to drive safely and yield appropriately. It also signals traffic police that the vehicle has a minor issue and is slowing down, and should not be treated as a traffic violation.

[QuinnFitz]

As a veteran truck driver with ten years of experience, turning on your hazard lights during highway traffic jams is absolutely a survival skill! Hazard lights are the highest alert signal for vehicle emergencies, far more noticeable than regular brake lights. When you see a sea of flashing red hazard lights in your rearview mirror, it's like Morse code from the road conditions—hitting the brakes immediately is the right move. Experienced drivers know that activating hazard lights can alert vehicles behind from as far as 500 meters away, especially during rainy or foggy conditions when visibility is poor—those red flashes could be a lifesaving signal. Don't worry about the minor battery drain; last time during a traffic jam on the Shenhai Expressway, it was the synchronized hazard lights from several cars ahead that prevented a ten-vehicle pileup in our convoy.

[StellaDella]

Last time I attended the traffic police safety lecture, I finally understood that traffic regulations are clearly written in black and white. If a motor vehicle stops on the highway due to a malfunction, hazard lights must be turned on. Although traffic jams don't count as malfunctions, they essentially create sudden road blockages. I've watched accident footage from the traffic police's phone—those multi-car pileup scenes. In cases where the leading car had hazard lights on, the following vehicles' braking distance was shortened by an average of 40 meters. Now whenever I encounter traffic congestion while driving, I immediately turn on my hazard lights—this gives trailing vehicles extra reaction time. Especially at night, when brake lights come on some drivers might react too slowly, but flashing hazard lights act like constantly waving warning flags.

[SanLaila]

Have you noticed that turning on hazard lights during highway traffic jams has become an unspoken rule? Last week, on my way back from Hangzhou to Shanghai, stuck on the Hukun Expressway, when the cars ahead simultaneously started flashing their hazard lights, I knew something was wrong. Sure enough, ten minutes later, I saw a five-car pile-up ahead. This action is like a herd of bison signaling danger during migration—the leading cars use their hazard lights to warn those behind: 'There's trouble ahead, slow down!' Once, driving a new car and unaware of this custom, I didn't turn on my lights during a jam. The bus behind me honked frantically, flashed its high beams, and the driver rolled down his window to yell, 'Turn on your hazards!' Now I understand—it's not just about self-protection, but a chain of safety for the entire traffic flow.