Whenever a long queue is detected at the metered ramp, the signaltiming should be adjusted to reduce the traffic flows entering the ramp. 當管匝道上排隊較長(cháng)時(shí),系統將通過(guò)自動(dòng)調整來(lái)減少進(jìn)入匝道的車(chē)流量,以保證匝道控制系統的有效性,避免匝道排隊過(guò)長(cháng),減少高速公路癱瘓的可能性。