When should a rider check their mirrors before making a lane change?

Answer: B — Immediately before the lane change and upon entering the new lane

The correct choice emphasizes the importance of situational awareness and safety when changing lanes. Checking mirrors immediately before making a lane change is crucial for assessing the space and traffic around you. This action allows the rider to scan for any potential hazards, such as vehicles or cyclists that may be in the blind spots or approaching from behind. Furthermore, checking mirrors upon entering the new lane ensures that the rider confirms the lane is clear and that there are no obstacles or vehicles encroaching on the newfound space. This two-pronged approach reduces the likelihood of collisions and enhances the rider's overall safety on the road. In contrast, only checking during a traffic jam or striking a methodical daily routine does not provide the necessary attention to changing traffic conditions, while checking only once during the lane change limits the rider's awareness of their surroundings. Failing to assess the environment adequately can lead to dangerous situations while navigating through traffic.