When you want to overtake quickly on the highway, do you need to turn on the left turn signal?

Many people's answers did not explain what the main question was asking. They personally understand the main meaning of the question: "When the vehicle is driving normally in the fast lane, and when there is a vehicle in the right lane, they also use the turn signal to overtake." In fact, this is a driving habit left by old drivers, and now many new drivers use it. I am using it because it has a really good reminder effect.

This veteran driver’s habit can be traced back to the 1990s or even earlier. The construction of highways was relatively weak at that time, and the design principles were different from now. At that time, the design of highway lanes was based on the principle of "passing lanes, driving lanes, and emergency parking areas." Now they are all designed as "hourly lanes" and the concept of so-called passing lanes no longer exists.

In the early days, there were many one-way and two-lane highways. Most of the drivers at that time still followed the habit of driving in the lane and going to the overtaking lane when overtaking. So as long as they reach the passing lane, they will inevitably change lanes and turn left. In addition, police or cameras will indeed monitor this behavior, which is called "not allowed to occupy the passing lane for a long time." There used to be a lot of signs on the highways.

Later, more and more cars got on the highway, especially many large trucks in the lane. It was troublesome for cars to change lanes frequently. In addition, the ruts in the lane were uncomfortable for large trucks, so some cars started driving in the passing lane for long periods of time, since there were only two lanes. In order to prevent passing large trucks from changing lanes and overtaking, car drivers turn left for a long time to alert the large trucks in the right lane. Additionally, they prevent police or cameras from turning on their left turn signal to indicate they are overtaking.

Now, the design principles of highways have changed. Instead of distinguishing between passing lanes and lanes, they are divided into speed lanes. So in theory, as long as the driver drives along the original lane, there is no lane change. Even if the vehicle passes the right lane, there is no need to turn on the turn signal.

But in actual driving, I usually turn on the left turn signal selectively. On a highway with many lanes, when a car passes the right side, the turn signal is generally not turned on when the speed is 120-110, because the driver on the opposite side will not change lanes if he observes it, and there is no need to turn on the light if he does not observe it. But if there are few lanes on the highway, especially when overtaking a large truck at a slow speed, the left turn signal will be turned on to remind the large truck in the right lane not to change lanes and overtake. If large trucks are queuing up, their headlights may flash, because large trucks may be queuing up to overtake, so turn on the turn signal to prompt large trucks, because the speed difference is large and the distance between vehicles is inaccurate. Turning on the turn signal tells the truck driver that I have started overtaking and you don't have much time to change lanes.