To understand the **order of priority** among different types of traffic signals, it is important to know which one we must obey first in situations where multiple signals may exist simultaneously.

1. **Traffic officers:**
**Traffic officers** have the highest priority. Their signals and orders must be obeyed before any other signal. This is because officers can manage traffic in real-time and adapt to specific situations that fixed signals cannot foresee.


2. **Traffic lights:**
After officers, **traffic lights** are the next priority. Traffic lights regulate the flow of traffic automatically and are crucial for maintaining order at intersections and crossings.


3. **Road markings:**
Finally, **road markings** on the road have the lowest priority. These include painted lines and other signals on the pavement that guide the movement of vehicles.

Therefore, the correct order of priority is: **officers, traffic lights, and road markings**. This order ensures that traffic is managed efficiently and safely, prioritizing direct human intervention when necessary.