What should a rider check before changing lanes to the left?

Before changing lanes to the left, it is essential for a rider to check their left mirror and look to the left. This practice is crucial because it allows the rider to see any vehicles or obstacles that may be in their blind spot on the left side, which is not visible in the mirrors alone. Checking the left mirror provides a view of the traffic in the adjacent lane, while physically turning the head to look left ensures that the rider has a comprehensive view of the environment. This dual-check process helps to prevent accidents caused by merging into a lane occupied by another vehicle or other hazards.

While checking the right mirror, looking through the rearview mirror, and checking the speedometer have their own importance in safe riding, they do not serve the specific purpose of ensuring safety when changing lanes to the left. The right mirror is more relevant for observing traffic on the opposite side, and the rearview mirror primarily aids in monitoring vehicles behind you. In contrast, maintaining an awareness of your speed is essential for safe riding overall, but it is not directly related to the act of changing lanes in that moment.