How many meters in advance should turn signals be activated according to traffic laws?

[LeEmmett]

On highways, turn signals should be activated at least 300 meters in advance, while in urban areas, they should be activated 3 to 5 seconds beforehand. Here is additional information: 1. The three yielding principles for turning: Yield to vehicles coming from the right; turning vehicles must yield to vehicles going straight; for vehicles approaching from opposite directions, vehicles turning right must yield to those turning left. 2. Prerequisite: When approaching an intersection without traffic signals, police direction, or any traffic signs or markings, vehicles should stop and observe before entering the intersection, then determine the right of way based on the three yielding principles.

[McBraxton]

Yesterday I witnessed a rear-end collision caused by a lane change without signaling. Traffic regulations clearly state: turn signals must be activated at least 50 meters before turning, and for urban lane changes, indicators should flash at least 30 meters in advance. On highways, extra caution is required - signals must be given over 100 meters beforehand. These distances aren't arbitrary figures; the longer the vehicle and the higher the speed, the less reaction time trailing drivers have. I remember once driving my friend's 5-meter-long Mercedes at 80 km/h - even though I signaled a full 120 meters in advance, the car behind still honked in protest.

[JamesMarie]

Driving instructors often say 'turn signals are the language of cars'. The legal requirements are quite specific: activate the turn signal 50 meters before turning and 30 meters before changing lanes. In actual practice, more flexibility is needed – you need to signal much earlier when encountering large trucks, and turn signals should be activated even sooner on rainy days when road surfaces are reflective. From my experience driving different vehicle types: 3 seconds of reaction time is sufficient for lane changes in compact cars, but when driving a 7-seater MPV, you should double the legal distance requirement.

[EdenLynn]

Asked a traffic police friend: Signaling 30 meters before changing lanes is a basic requirement, but actual tests show 30 meters only provides 1.5 seconds reaction time for sedans. At 60km/h, the true safe distance should exceed 40 meters. When merging from highway ramps onto main lanes, they recommend signaling 150 meters in advance. Once driving on a national highway in foggy conditions, I turned on my right turn signal 200 meters ahead and still got a thankful flash from the car behind.

[VonBrandon]

From the perspective of vehicle signal system design on turn signal rules: Traffic regulations require a 50-meter warning before turning and a 30-meter warning before changing lanes. This is not just a simple distance setting—at a speed of 60 km/h, 30 meters is equivalent to only 1.8 seconds of travel time. Considering human reaction delay + vehicle braking distance, an actual distance of 80 meters should be allowed for true safety. When driving a heavy SUV, I usually wait an extra 3 seconds before turning.

[KimberlyLynn]

According to Article 57 of the Road Traffic Safety Law Implementation Regulations: Turning vehicles must activate their turn signals at least 50 meters in advance. The lane-changing distance is specified in the Motor Vehicle Driver's Handbook, requiring a 30-meter warning. Many drivers neglect this on actual roads—traffic management statistics show that 23% of rear-end collisions are caused by signaling less than 20 meters in advance. A helpful tip to remember: 'On highways, count four seconds before changing lanes; in urban areas, signal before passing three streetlight poles.' Extra caution is needed for vehicles over 5 meters in length, which require 50% more signaling time.