What conditions must be met for a train to proceed without cab signals after passing a block signal?

For a train to proceed without cab signals after passing a block signal, visual confirmation of a green signal indicating that the track ahead is clear is essential. This ensures that the train is entering an area where it is safe to proceed without the automated guidance of cab signals. The green signal confirms that the track is not only clear of obstacles but also indicates that the route is set properly for continued movement. This level of visual confirmation is a critical safety measure, allowing the operator to make informed decisions based on the visible state of the railway environment.

It is also crucial to note that conditions such as the indication of slow speed, previous clearance from the night before, or dispatcher authorization do not provide sufficient assurance for the safe operation of a train in the absence of cab signals. A green signal serves as a definitive indicator that all safety protocols for the current stretch of track have been satisfied, making it the necessary condition for proceeding.