Which numbers are assigned to the left turn movements in a vehicle phase?

Left turn movements in traffic signal phases are typically assigned odd numbers. The reasoning behind this is rooted in the traffic control conventions that aim to clarify and distinguish between different movements at signalized intersections. Assigning odd numbers to left turn movements helps ensure that they are easily recognizable and manageable, especially in complex signal configurations or during the timing adjustments for various phases.

This numbering convention serves practical purposes in both signal design and operational efficiency. By utilizing odd numbers specifically for left turns, it aids traffic engineers and technicians in quickly identifying left turn phases during diagnostics or programming of traffic signals, thereby making the system clearer and reducing the likelihood of confusion during signal operations.

The incorrect choices stem from other numbering conventions that do not apply in this context. For example, even numbers and numbers divisible by three are not specifically allocated to left turns, as they are commonly reserved for different movements or phases altogether. Sequential numbers may refer to the overall count or the order of movements but lack the specificity required for identifying left turn phases in traffic signal operations.