convergence of control: railway signal lights

cautionarysignals cloudskybackgrounds communicationtools commuterrails controlsystems directionalguidance electriclines electricalengineering guidancesystems highvoltagelines industrialequipment infrastructure journeyguidance journeyregulation metalgantries navigationtools operationalsafety outdoorsignaling overheadsignals powerlines precisionnavigation publictransitsystems railnetwork railsafetyfeatures railtransportation railroadcrossing railroadinfrastructure railway regulatorysignals routemanagement safetyequipment signallights signalingdevices signalingequipment signals steelstructures tracksafety tracksidesignals trafficcontroldevices trafficlights trainsignals traintracks transitcontrol transportindustry transportation travelpathways urbanrailwaysystems weatheredfacilities convergence control: signal lights overhead cloudy sky guiding trains journey