The traffic management department of H City said that compared with last year, the road traffic in the city's urban area has improved significantly this year. The person in charge of this department believes that this is due to the city's employment of a large number of transportation assistants. Which of the following would not undermine the person in charge most? ['Earlier this year, a special meeting was held in H City to study and rectify traffic problems.', 'Many experts believe that hiring a large number of transport coordinators is costly.', 'Earlier this year, the new road expansion project in the urban area of H City was just completed.', 'This year, city H has imposed strict restrictions on vehicles entering the urban area. Many large trucks and foreign vehicles cannot enter the urban area during the "peak" period of traffic.']