Why should you signal left when entering the highway from the ramp?

[Rick]

Using the left turn signal when entering the highway from the ramp is a legal requirement. When a motor vehicle enters the highway from the ramp, it must activate the left turn signal and merge into the lane without obstructing the normal flow of vehicles already on the highway. When exiting the highway, the vehicle should activate the right turn signal, enter the deceleration lane, reduce speed, and then exit. Additional information: 1. Entrance and exit ramps: These are auxiliary connecting sections for entering and exiting the main road, which can be "at-grade ramps" or "interchange ramps." They are the main traffic infrastructure constituting road interchanges. 2. Up and down ramps: These are auxiliary connecting slopes for entering and exiting elevated roads, moving upward or downward, usually "interchange ramps." 3. Direct ramp: Places the right-turn lane on the right side. 4. Indirect ramp: Places the left-turn lane on the right side, using a loop to connect to other roads. 5. Semi-direct ramp: Similar to the indirect ramp but without a loop, instead using a longer, more undulating elevated road as the connecting ramp. 6. U-turn ramp: A ramp designed for U-turns.