Railway network. Rail network level crossings

Railway network. Rail network level crossings. They distinguish between steps with acoustic and light signals, with semi-barriers and without protection.铁路路网。铁路平交道口。此类平交道口依据防护形式可分为三类：配备声光信号装置的道口、设置半防护栅栏的道口以及无任何防护措施的道口。