Level crossing signals
Automated level crossings are found in most developed nations and vary greatly, but this page in particular is specific to the United States.In some countries (such as the Czech Republic or Slovakia) there is also a flashing white light, which means that it is possible to pass the level crossing at a higher speed than generally allowed.A railroad track occupied by a train or other electrical shunt can be viewed as a single-turn inductor shaped like a hairpin.The absolute magnitude of this voltage and its rate of change can then be used to compute the amount of time remaining before the train arrives at the crossing, assuming it is running at a constant speed.The earliest level crossing predictors used analog computers to perform this calculation, but modern equipment uses digital microprocessors.
Soo LineTrout Lake, MichiganBelgrano Norte LineFlorida Oesteroad vehiclesrailroadlevel crossingsflashing red lightscrossbuckCzech RepublicSlovakiabarrierstatesWigwag (railroad)WigwagpendulumAlbert Huntmechanical engineerSouthern CaliforniaPacific Electricinterurban streetcarelectromagnetsarmatureMagnetic Signal CompanyAustraliaNortheast, MinneapolisStanford Research InstituteSouthern Pacific CompanySouthern Pacific RailroadUnion Pacific Railroadinductorinductancealternating currentOhm's Lawanalog computersmicroprocessorsLevel crossingBoom barrierE-signalRailway signallingBlock systemsAbsolute block signallingAutomatic block signalingCentralized traffic controlCommunications-based train controlDirect traffic controlEuropean Train Control SystemMoving blockRadio Electronic Token BlockTrack Warrant ControlTrain order operationSignalling controlBlock postIntegrated Electronic Control CentreInterlockingLever frameRail operating centreSolid State InterlockingWestlock InterlockingSignalsApplication of railway signalsCab signallingNorth American railroad signalsRailway semaphore signalAxle counterTrack circuitTrack circuit interrupterTreadleTrain protectionAdvanced Civil Speed Enforcement SystemAutomatic train controlAutomatic train operationAutomatic train protectionAutomatic Train Protection (United Kingdom)Automatic train stopAutomatic Warning SystemAutomatische treinbeïnvloedingBaliseCatch pointsChinese Train Control SystemCityflo 650 CBTCContinuous Automatic Warning SystemContrôle de vitesse par balisesEBICABIntegra-SignumInteroperable Communications Based SignalingCrocodileKorean Train Control SystemLinienzugbeeinflussungPositive Train ControlPulse code cab signalingPunktförmige ZugbeeinflussungRS4 CodiciSelTracSistema Controllo Marcia TrenoSlide fenceTrain automatic stopping controllerTrain Protection & Warning SystemTrain stopTrainguard MTTransmission balise-locomotiveTransmission voie-machineWayside hornAdtranzAlstomAŽD PrahaFederalGeneral ElectricGriswoldHitachiHyundai RotemMagneticProgress RailSafetranSiemensSmith and YardleyThalesUnion SwitchWestinghouse Brake & SignalWestinghouse Rail SystemsTransport CanadaBavariaBelgiumCanadaFinlandFrance