時(shí)間平均車速)PPT優(yōu)秀課件

1、13.2 Definition of SpeednTime mean speed (TMS，時(shí)間平均車速) - defined as the average speed of all vehicles passing a point on a highway over some specified time period nSpace mean speed (SMS，空間平均車速) - defined as the average speed of all vehicles occupying a given section of a highway over some specified t

2、ime period 2nTMS is a point measure, while SMS is a measure relating to a length of highway or lane nSMS is often used in traffic flow theory study at macroscopic level while TMS is used for engineering studynTMS SMS3nAverage travel speed and average running speed （平均行程，行駛速度) - Average travel speed

3、= distance /travel timeAverage running speed = distance/running timeRunning time = travel time - stopped delays 4nOperating speed （運(yùn)營速度）- defined as the maximum safe speed at which a vehicle can be conducted in a given traffic stream, without exceeding the design speed of the highway segment.nCritic

4、al speed or Optimal speed (臨界車速) - defined as the speed at which maximum flow rate (capacity 通行能力) can be achieved (or at which gas consumption of vehicles is at the lowest) 5nPercentile speeds （百分位速度）- is a speed below which the stated percent of vehicles in the traffic stream travel 60.0%0.0%10.0%

5、10.0%20.0%20.0%30.0%30.0%40.0%40.0%50.0%50.0%60.0%60.0%70.0%70.0%80.0%80.0%90.0%90.0%100.0%100.0%30303232343436363838404042424444464648485050525254545656585860606262646466667nIn traffic engineering, 85th percentile speed is often used as a measure of the maximum reasonable speed for the traffic stream (upper limit), while the 15th percentile speed may be used as a measure of the minimum reasonable speed for the traffic stream. The 50th