This paper makes reference to traffic insurance,analysises the necessity of putting engineering quality insurance in force recently, discusses how to putting engineering quality insurance in force, particularly how to putting forcible insurance in force.

Aiming at the problems of traffic jam in road crossing in cities,it analyses the problems existed in flat crossing existing situation,according to the traffic character of the flat crossing of road,from the canalization,the safe crossing of passerby and the traffic control equipment it discusses the design of the improving of flat crossing,to increase the traffic function of crossing.

To these problems such as ecological crisis,traffic jam, and old city reconstruction,etc.

This essay, from the viewpoints of microeconomics, concludes that it can not throughly solve the traffic jam problems simply by means of widening the roads.

Queuing Theory Method for Traffic Impedance Analysis;

This article intervention study in the traffic impedance of urban road sections and intersections, and established a relatively detailed structure of impedance function.

The line in the road network diagram and its traffic impedance are defined,the method to forecast line\'s traffic impedance with real-time traffic data is introduced,and the regional and gradational algorithm of the dynamic optimal driving path is set forth and illustrated.