Why can't you drive straight in a sawtooth lane?

[DiTaylor]

Sawtooth lanes allow straight driving when the traffic light is green, but with fixed time restrictions. Most commonly during peak hours in the morning and evening, this lane can be used as a left-turn lane to alleviate traffic pressure. This lane serves dual purposes as both a left-turn lane and a straight-driving lane. Below are the specific details: 1. Function: Sawtooth lane markings are a type of deceleration marking, which includes both horizontal and vertical markings. Their purpose is to create an optical illusion and a sense of pressure when vehicles are driving at high speeds, prompting drivers to instinctively reduce their speed in advance, thereby decreasing the occurrence of traffic accidents. The sawtooth lane helps alleviate traffic congestion and serves as an effective traffic flow guide. 2. Note: Sawtooth lanes are also known as variable lanes. Although they may have straight arrows marked on them, the presence of sawtooth markings means that during certain time periods, they may change to left-turn lanes. Therefore, it's essential to understand the designated times for straight driving and left turns. These times are usually indicated on roadside signs or traffic lights near the sawtooth lane, so be sure to check them carefully.