How many meters in advance should the turn signal be turned on?

[SanArcher]

The turn signal should be turned on 10 to 30 meters in advance. Here is some knowledge about turn signals: 1. Introduction: The turn signal is an important indicator light that is turned on when a motor vehicle is turning to alert vehicles and pedestrians in front, behind, and to the sides. The turn signal tube uses a xenon tube, controlled by a single-chip microcomputer circuit, with left and right alternating flashes working continuously. The turn signal uses a flasher to achieve light flashing. It can mainly be divided into three types: resistance wire type, capacitor type, and electronic type. 2. Structural principle: The resistance wire type can be further divided into thermal wire type (electrothermal type) and wing type (bounce type), while the electronic type can be divided into hybrid type (with contact-type relays and electronic components) and fully electronic type (without relays). For example, the bounce-type flasher uses the principle of current thermal effect, with thermal expansion and contraction as the driving force, causing the spring plate to produce sudden movements to connect and disconnect the contacts, achieving light flashing.

[LeMalachi]

Regarding how many meters in advance to turn on the turn signal, I think it depends on the specific road conditions. On ordinary urban roads, it is recommended to turn on the turn signal at least 30 meters before turning, giving the following vehicles enough time to react. For example, when making a left turn, you should signal when you see the traffic light ahead at about the distance of two utility poles. On highways, you need to signal even earlier when changing lanes, at least 50 to 100 meters in advance, because the speed is higher and the reaction time is shorter. What annoys me the most while driving are those who change lanes suddenly without signaling or signal just as they turn, which is particularly prone to causing rear-end collisions. Additionally, at night or during rainy weather, you should signal even earlier, as poor visibility requires more advance warning. Remember, this is not a rigid rule; the key is whether you can make your intentions clear to the surrounding vehicles.

[DiEmmett]

As an experienced driver, my advice is to flexibly master the timing of turn signals. At normal city speeds, about 30 meters in advance is appropriate—you can estimate by counting streetlight poles. But be mindful of varying situations: lane changes require more distance than turns, especially when changing across four lanes where 50 meters is ideal. Once, I followed a car entering an off-ramp; they signaled 100 meters ahead, giving me ample time to slow and change lanes—a habit worth learning. However, signaling too early for turns can mislead straight-driving vehicles, like activating your indicator 200 meters before an intersection, making others think you're turning immediately. In short, balance safety with clarity in your signaling distance.

[HectorAnn]

During driving lessons, the instructor repeatedly emphasized that turn signals must be activated in advance. The standard procedure is to turn on the signal 30 meters before a turn, and even earlier for lane changes. In actual driving, this distance provides following vehicles with exactly 3 seconds of reaction time. For example, if a following car is traveling at 40 km/h, 30 meters equates to 2.7 seconds, which is sufficient for slowing down or yielding. A common mistake beginners make is signaling too late—only pressing the switch when they're about to turn, leaving no time for following vehicles to react. Once, while I was reversing into a parking space and signaled just 10 meters in advance, an electric scooter nearly collided with me. Now, I've developed the habit of moving my hand to the signal before touching the steering wheel. In special weather conditions, additional precautions are necessary; on rainy days, I increase the signaling distance by 20%.