京津塘高速公路秋冬季低能见度及应对措施

Poor visibility on Jingjintang Expressway in autumn/winter and relevant measures

利用2007年10-12月沿路布设的气象自动站相对湿度资料和能见度资料,初步分析了京津塘高速公路各路段低能见度事件的分布特点,指出秋冬季的低能见度天气分布及成因呈现明显的区域特征:低于1 km的低能见度事件,以塘沽局路段出现的概率最大,达到20%;小于200 m的低能见度事件,以泗村店路段出现概率最大,塘沽局次之;马驹桥路段出现不同视程低能见度事件的概率均为最小。当能见度小于1 km时,各路段车辆须减速;当能见度小于200 m时,建议马驹桥路段限速,塘沽西和泗村店路段在对车辆严格限速的同时,要密切关注能见度变化,随时准备封路,而塘沽局路段最好立即封路。进一步讨论了低能见度事件中相对湿度的分布特征,指出各路段不同视程的能见度事件主要是由雾、霾及其混合物等不同天气现象影响造成的。

Based on relative humidity and visibility observation of automatic meteorological station along Jingjintang expressway, poor visibility cases at every section of the expressway were studied. It shows that, poor visibility and it＇ s causes are obviously regional. The poor visibility probability is the highest and up to 20 percent at Tanggu Bureau section with visibility below 1 kilometer, while it is the highest at Sieundian section with visibility below 200 meters, and lowest at Majuqiao section for each poor visiblity distance. Different suggestion are given for each section at every visual range poor visibility as following. （ 1 ） The speed of vehicles on every section should slow down in the ease of poor visibility below 1 kilometer; （2） At the condition of poor visibility less than 200 meters, the speed should be probably restricted at the Majuqiao section, and the speed should not only be severely restricted at Tanggu West and Sieundian sections, but also give close attention to the visibility change and be ready to close the traffic. Tanggu Bureau section had best to close the traffic immediately. Moreover, relative humidity during different visual range poor visibility was discussed. It is pointed out that poor visibility cases at different sections of Jingjintang Highway is caused by different weather phenomena such as fog, haze or their mixture.