Metropolitan Transportation Authority (MTA) Assistant Conductor Practice Test

What is a block limit signal used for?

1. A place where a block limit signal is displayed

2. A device to measure train speed

3. A communication tool between conductors

4. A signal for emergency stops

The correct answer is: A place where a block limit signal is displayed

The function of a block limit signal is to indicate the boundaries of a block section on the railway. This type of signal is crucial for train operations, as it helps maintain safe distances between trains by designating where a train is authorized to operate within a block. When a block limit signal is displayed, it informs the crew that they have reached the limit of the block, allowing them to proceed with caution or adhere to instructions regarding train movements within that section. Understanding the context of the other answers can provide insight into why they do not accurately describe a block limit signal's purpose. For example, measuring train speed is the role of speedometers or other related devices, while communication tools between conductors typically involve radios or intercom systems rather than signals. Similarly, while signals are important for managing train traffic, a block limit signal is specifically designed to define the extent of a block rather than being a generic signal for emergency stops. Emergency stop signals have distinct purposes and usually indicate that immediate action is required for safety reasons.