What is the primary purpose of signals such as lanterns along the tracks?

The primary purpose of signals such as lanterns along the tracks is to guide trains during maintenance operations. These signals help operators and crews understand track conditions, potential hazards, and any ongoing maintenance work that might affect train movement. Proper signaling is crucial in ensuring that trains are directed safely around work zones, preventing accidents and ensuring that maintenance crews can perform their tasks without interference.

While signals may have an indirect impact on passenger safety by preventing accidents, their main function in the context of this question is specifically about guiding operations during maintenance. Enhancing train speed or regulating train schedules are more related to other types of signals or operational protocols that focus on train movement rather than maintenance guidance.