When is it permissible to exceed the maximum speed limit under SPA working?

The correct scenario involving the permissibility to exceed the maximum speed limit under SPA (Special Purpose Authorisation) working is linked to the specific context in which a train is operating. The option indicating that it is permissible when clear of a level crossing reflects a relevant operational practice. Specifically, this can occur when the safety of the train and passengers, as well as compliance with operational protocols, is ensured after the level crossing has been cleared.

In railway operations, level crossings typically require trains to reduce speed for safety reasons. Once the crossing is clear, there may be circumstances where a train could be permitted to increase its speed, provided that it is safe to do so and in accordance with the relevant regulations and authorizations.

The nature of SPA working emphasizes the importance of safety protocols and adherence to specific rules, which can vary based on the scenario. Thus, once the conditions surrounding a level crossing are met, there may be an allowance for increased speed.

This understanding hinges on operational guidelines that prioritize safety while permitting some flexibility in train operation under controlled circumstances.