Description on multi-traffic flow s characteristics is the basis for the study on theory of multi-
traffic flow. This paper analyzes the vehicle s type composition of the high-class highway in the future,
specify the scope of study on theory of multi-traffic flow, and puts forward two basic concepts, namely
randomizing degree and viscosity. Through theoretical calculation and practical measuring, gained the speed
pattern and jamming density of the multi-traffic flow are obfained.