In order to relieve traffic congestion, the city of Gastner built a new highway linking several of the city’s suburbs to the downtown area. However, the average commute time for workers in downtown Gastner increased after the new highway opened.
Which one of the following, if true, most helps to explain the increase in average commute time?
Most people who work in the downtown area of Gastner commute from one of the city’s suburbs.
If most downtown workers commute from the suburbs and the new highway links the suburbs to downtown, shouldn’t most downtown workers’ commute time have decreased? (A) doesn’t provide a consequence of the highway that explains why commute time increased after the highway opened.
The location of the new highway is most convenient for people who commute to and from Gastner's largest suburbs.
We need a consequence of the highway that outweighs its intended benefits and explains how traffic patterns changed and commute time increased after it opened. The highway’s convenience for people from the largest suburbs doesn’t explain these changes.
Shortly after the new highway was opened, several suburban roads connecting to the new highway were upgraded with new stoplights.
We don't know if new stoplights on suburban roads would increase or decrease commute times. Maybe all the suburban roads previously had stop signs, which are generally much slower than stoplights. We still need a consequence of the highway that causes increased commute times.
At the same time the new highway was being built, road repair work was being done on important streets leading to downtown Gastner.
We need a consequence of the highway that explains why workers’ commute times increased after the highway opened, not while the highway was being built.
In Gastner’s downtown area, traffic on the roads near the new highway became more congested after the new highway was opened.
This explains a consequence of the highway that caused changes in downtown traffic and increased commute times. Even though it was intended to relieve congestion, it actually made downtown roads more crowded, increasing overall commute times for downtown workers.