In America, where the ownership of private cars is most prevalent, President Bush made the following statement when announcing transportation measure three years ago: "Because America has too strongly emphasized convenience to individuals, roads have been spreading unchecked, and the unpleasant side effects of the rapid growth in private vehicles have already offset their benefits."
擁有私人汽車數量佔世界第一位的美國，三年前，布希總統的一份運輸政策就指出，由於美國太重視個人的便利，公路無節制地開發，私人交通工具大量成長，使汽車帶來的負面影響，已將它的利益抵銷掉。