What procedure must be followed if the train to be met has not arrived at meeting points?

When a train is expected to arrive at a meeting point but has not done so, the proper procedure is to ensure that communication is established regarding the missing train. The conductor or engineer contacting the block operator or train dispatcher is critical as it allows for the verification of the situation and ensures safety. By notifying the relevant parties, they can receive clear instructions on how to proceed, and it also provides the opportunity to assess any potential issues with the train that should be addressed. This communication protocol is vital to maintain safety and operational integrity on the railway, preventing unforeseen complications that might arise from an uncommunicated delay.

The other options, while they seem plausible, do not directly promote safety and clarity in operations. Waiting for additional instructions without communication leaves the crew in uncertainty, proceeding with caution without knowing the status of the other train could lead to risky situations, and continuing without communication is dangerous and goes against standard operating procedures.