What does a red X light signal indicate about lane usage?

A red X light signal indicates that vehicles must not use the lane. This signal is a clear directive for drivers to recognize that the lane is closed to traffic. Such a signal is typically used when the lane is either under maintenance, in use for other purposes such as bus or emergency vehicle access, or when it poses some form of danger to drivers. Recognizing and adhering to these signals is crucial for maintaining safety on the road.

The incorrect options reflect different scenarios that are not suitable under a red X signal. For example, stating that all vehicles must use the lane misunderstands the clear prohibition communicated by the red X. Similarly, the options regarding bicycles or emergency vehicles do not apply, as the primary function of the red X is to keep all traffic out of that particular lane for safety and operational reasons.