The heavy traffic in Masana is a growing drain on the city' s economy--the clogging of the streets of the central business district alone cost the economy more than $1. 2 billion over the past year. In order to address this problem, officials plan to introduce congestion pricing, by which drivers would pay to enter the city's most heavily trafficked areas during the busiest times of the day. Which of the following, if true, would most strongly indicate that the plan will be a success? ['Planners expect that, without congestion pricing, traffic in Masana is likely to grow by 6 percent in the next five years.', 'In other urban areas, congestion pricing has strongly encouraged carpooling (sharing of rides by private commuters).', "Over 30 percent of the vehicles in the city's center are occupied by more than one person.", 'Approximately one-fifth of the vehicles in the central business district are in transit from one side of the city to the other.']