When should high beams be displayed while operating a train?

High beams should be displayed at all times outside of tunnels and when entering "H" platforms in Newark because this practice enhances visibility and safety for both the train operators and other rail personnel. Using high beams in these conditions helps illuminate the tracks and surroundings, making it easier to spot potential hazards or obstructions.

In contrast, relying solely on high beams at night or during adverse weather conditions (as suggested in other options) does not account for specific operational guidelines that emphasize increased safety measures in particular areas, such as platforms or during transitions between different types of rail environments. Following these guidelines ensures that the train is visible and enhances communication with crew members working on the ground.