当客货运成本支出一定时，要完成一定的发送量，还要使发送量的行程及运程达到一定值才能实现盈利目标，此值即盈亏临界点。结合１９９７年贵阳分局实际，客货运管内发送运输、旅客直通发送运输都是盈利的，而货物直通发送运输由于清算调节系数低而造成亏本。 When the passenger and freight costs a certain expenditure, to complete a certain amount of delivery, but also to send the amount of travel and travel to reach a certain value in order to achieve profitability, this value is the breakeven point. Combined with the actual situation in Guiyang Branch in 1997, both passenger and cargo transport pipelines are able to send and receive goods transparently and passengers are directly sent and transported, which is profitable. However, due to the low liquidation and adjustment coefficient, goods are directly sent and lost, resulting in a loss.