Final answer:
Two main reasons to change lane positions are to avoid hazards and to overtake slower vehicles. Excessive lane changing can increase fuel consumption rather than reduce it.
Step-by-step explanation:
There are multiple reasons to change lane positions while driving, but two primary reasons are to avoid hazards on the road and to overtake slower vehicles. Changing lanes to avoid hazards is crucial for maintaining safety on the road. If a vehicle, pedestrian, debris, or any other obstacle presents a danger in your current lane, it is imperative to safely change lanes to prevent an accident. Additionally, overtaking slower vehicles is a common reason for changing lanes as it helps maintain the flow of traffic and allows faster-moving vehicles to pass safely.
Regarding fuel consumption, changing lanes excessively can actually lead to increased fuel use due to variations in speed and acceleration. Therefore, it is important to change lanes thoughtfully and when necessary to optimize fuel efficiency. Lastly, changing lanes does not inherently increase a vehicle's speed; this is controlled by the driver's use of the accelerator.