Read the passage. Paragraph 1: Smart traffic lights can adjust signals based on real-time vehicle flow. City leaders often describe them as a way to reduce congestion. Paragraph 2: Shorter waits at one intersection do not guarantee a faster trip across town. If the next major road remains clogged or if pedestrians receive less crossing time, the apparent improvement may simply move the delay elsewhere. Paragraph 3: Evaluating the technology requires measuring the whole transportation system, not just one signal. In this passage about smart traffic lights, paragraph 2 primarily functions to