The city of Oakhaven has experienced a significant increase in weekday morning traffic congestion over the past five years, particularly on its main thoroughfare, Central Avenue. To alleviate this, the city council proposes to implement a "congestion charge" – a fee for vehicles entering the downtown area, including Central Avenue, between 7 a.m. and 10 a.m. on weekdays. The council argues that this charge will reduce the number of vehicles, thereby easing congestion and shortening commute times for those who do choose to drive and pay.
Which of the following, if true, would most strengthen the argument that the city council's plan will achieve its goal?