The NEMA TS-2 standards expand the TS-1 requirements to include which of the following?

The NEMA TS-2 standards indeed expand upon the TS-1 requirements, particularly in the area of treatment of signal preemption. This is crucial for traffic signal operation because signal preemption allows for the priority of certain vehicles, such as emergency vehicles, to ensure they can pass through intersections without needless delays. The TS-2 standards provide more detailed specifications and guidelines for implementing effective preemption systems, thereby improving traffic flow and enhancing safety at intersections.

This focus on preemption reflects an understanding of the importance of prioritizing emergency response while maintaining the overall efficiency of traffic signals. The improvements in this area under TS-2 standards contribute to a more reliable and adaptive traffic control system, which is vital for urban planning and public safety.

While the other options may relate to broader traffic management concerns, they do not capture the specific enhancements made in the context of traffic signal control that are characteristic of the NEMA TS-2 standards.