<> variance of link travel time is proportional to the reciprocal of (link length)^(2/3) as well as proportional to the product of the number of links connecting to the two nodes at both ends of the link.<BR>怎么理解?</P>
variance of link travel time is proportional to the reciprocal of (link length)^(2/3) as well as proportional to the product of the number of links connecting to the two nodes at both ends of the link.的意思是行车时间这个随机变量的方差与路段的长度的2/3次方成反比,与路段两端(节点)所连接的高速公路路段数的乘积成正比。<BR>