我国现行的公路工程设计准则(以下简称准则)对桥梁人行道作了如下规定:“Ⅰ、Ⅱ级公路上的全部桥梁及Ⅲ级公路上采用净-7的桥梁,一律设人行道。Ⅲ级路采用净-8的桥梁,不设人行道。Ⅲ、Ⅴ、Ⅵ级公路采用净-6的桥梁,一般应设人行道:采用净-7的桥梁,一般不设人行道……”但从历年使用的情况来看,在远离市镇或桥长较短的桥梁上设置人行道的作用是不大的。桥梁人行道设置的目的,是为了保障行人安全,减少车辆肇事。根据历年来对肇事的调查,在线路上发生的较多,而在桥梁上发生的几乎没有。而一般的桥面净空是窄于路基宽度的,由此可见撞人肇事的原因,并不是由于路太窄、行人无处走而造成的;不按规定的高速行驶,才是车祸的根源之一。这里,还可以用计算来说明这个问题。准则规定Ⅲ级公路的行车最大密度为每昼夜3,000辆,假定在白天 China’s current highway engineering design guidelines (hereinafter referred to as the guidelines) on the sidewalks made the following provisions: “Ⅰ, Ⅱ grade roads and all the bridges on the highway Ⅲ -7 net of the bridge, all set sidewalks. Ⅲ grade road Net-8 bridge, no sidewalks.Ⅲ, Ⅴ, Ⅵ highway with a net -6 bridge, the general should be set sidewalks: the net -7 bridge, generally without sidewalks ... ”But from the calendar year to use the situation It does not seem that the sidewalks are located on bridges that are short distances from towns or bridges. The purpose of setting the bridge sidewalk is to protect pedestrian safety and reduce vehicle accidents. According to the investigation of the accident over the years, there have been more occurrences on the line and almost no occurrence on the bridge. The general deck clearance is narrower than the width of the subgrade. This shows that the cause of the collision was not caused by the road being too narrow and pedestrians are nowhere to go. The failure to follow the prescribed high speed is the root cause of the accident one. Here, you can also use calculations to illustrate this issue. The guidelines stipulate that Class III roads should be driven at a maximum density of 3,000 vehicles per day and night, assuming daytime