Which of the following statements is incorrect regarding NYCTA subway cars that are not married pairs?

The statement regarding NYCTA subway cars that are not married pairs being incorrect pertains to the configuration of the cars. Subway cars can vary in their design and operational capabilities, and saying that some have exactly four motors does not reflect the true variations in the designs of the fleet.

Many subway car models may have different numbers of motors depending on their design specifications, operational requirements, and intended use. For example, certain models might have more than four motors to provide the necessary power and performance, especially for cars that are part of larger, more articulated train sets.

In contrast, other statements accurately represent characteristics of NYCTA subway cars. Those cars do indeed have air conditioning, which is a standard feature for passenger comfort. Emergency brakes are also a critical safety feature, and while some systems may vary, it is not accurate to say that none have emergency brakes. Moreover, some cars are equipped with automated systems, which enhance operational efficiency and safety. Thus, the assertion that some cars have exactly four motors inaccurately limits the capabilities and specifications of NYCTA subway cars that are not married pairs, making it the incorrect statement in this context.