现在有更多的铁路公司正在失去其客货运输所占的市场份额,鲜有所赢。公路货物运输和私人小轿车是这场竞争的赢家。供其运营的公路网很少需要或根本不需要安全信号。在有些道口,集中设有路标,由驾驶员自己判断,其安全程度低于铁路。如果铁路要挽回损失、重新赢得市场份额,就需要改进服务、降低成本,包括降低铁路诸项成本中较为重要的用于信号系统的成本。上世纪中叶,手执信号旗的“警察”为活动臂板信号所取代。自此以后,铁路信号技术改变甚微。本世纪则经历了色灯信号取代机械信号,电动和电气控制先后取代信号楼和信号机之间的机械联锁装置。无论是在什么情况下,我们都潜意识地认为火车会突然出现在路网上的任何一点,还认为列车前后必须有一个运行间隔来保证安全。然而,铁 There are few more railway companies now losing their market share in passenger and freight transport. Road freight transport and private cars is the winner of this competition. The road network for which it operates has little or no need for safety signals. At some crossings, there is a centralized road sign, which is judged by the driver himself and is less safe than a railway. If railroads recover their losses and regain market share, they need to improve their services and reduce their costs, including reducing the more significant signal system costs associated with railroad costs. In the middle of the last century, the “policeman” with a hand signal was replaced by a signal for the active arm. Since then, the railway signal technology has changed little. This century has experienced a color light signal to replace the mechanical signal, electric and electrical control has replaced the signal between the signal and the mechanical interlock device. No matter under what circumstances, we subconsciously think that the train will suddenly appear on the road network at any point, but also that there must be a running interval before and after the train to ensure safety. However, iron