For example, the U.S. Manual on Uniform Traffic Control Devices (MUTCD) does not follow the symbol policy espoused by the Vienna Convention; for example signs for speed limits and forbidden parking are among the most visible differences.
舉例來說，美國的道路交通管理標誌統一守則（MUTCD）沒有按照維也納公約規定的標誌政策；例如速限和禁止停車的標誌是其中最明顯的差異。