The NEMA TS-2 standards expand the requirements from TS-1 to include what additional item?

The NEMA TS-2 standards indeed expand upon the requirements outlined in TS-1 by including the treatment of signal preemption. This is a critical function in traffic signal management, allowing for the priority of certain vehicles, such as emergency vehicles, ambulances, or public transit, thereby enhancing safety and efficiency in traffic operations. The inclusion of preemption procedures ensures that these priority vehicles can effectively manage their response times through traffic signals, which is a vital aspect of modern traffic control systems.

In contrast, while the other options touch on important aspects of traffic management, they are not specifically part of the expanded requirements set forth in the TS-2 standards. Signal timing optimization, real-time traffic data collection, and system diagnostics are all related to traffic operations and management but do not encapsulate the specific requirement for signal preemption that TS-2 addresses. Understanding the emphasis on preemption in the TS-2 standards highlights its role in facilitating coordinated responses for priority vehicles in traffic networks.