Flashing Lights plus Gates
Train activated warning devices include flashing lights and gates. Some crossings may be protected with flashing lights and no gates. Others may have both the flashing lights plus gates that drop across the roadway in front of approaching traffic. Motorists must stop whenever automatic signals are activated.
These automatic warning devices are expensive and are primarily used at crossings where there is a high risk of collisions between motor vehicles and trains due to the amount of roadway and/or train traffic, the crash history, and other factors.
It costs about $250,000 to equip one crossing with flashing lights and gates. The time required for the installation may take 18 months from project initiation to construction. The actual construction of active warning devices is the responsibility of the railroad. Once active warning devices are installed, the railroad is responsible for maintenance costs.
Who decides which crossings get active warning devices and who pays for them?
The owner of the public roadway at the crossing generally has the responsibility for deciding which crossings should have lights and/or gates and for the cost to install them. However, if a railroad creates a new crossing by extending a track across a roadway, the railroad is responsible for the cost to install the warning devices. Railroads and other entities may sometimes voluntarily help pay the cost to install lights and gates at other crossings, but in general there are no laws that require them to do so. However, INDOT does have the regulatory authority to order installation of lights and/or gates at any public crossing that INDOT has determined to be an extraordinary hazard, and to divide the costs among the various parties as appropriate.
How do signals work?
Equipment improvements continue to be made which means installations will vary in the way signals are activated. But all signals work on the principle of being activated when an approaching train reaches a certain distance from the crossing.
Train activated signals are operated from a signal control cabinet. When a train is detected, the controller determines when to activate the lights so that there is at least 20 seconds of warning before the train arrives. The controller sends a signal to the relays, which in turn send power to activate the flashing lights.
Note that a signal always operates from battery power, not the AC power line. AC power is used only to keep the batteries charged. In the event of an AC power failure, the signals will operate on batteries anywhere from several hours to several days, depending on the weather, the number of trains and other factors. However, if the batteries are run to depletion crossing gates will lower automatically due to gravity but the lights will no longer flash. Never go around a lowered railroad-crossing arm unless directed to do so by a police officer or railroad crew.
Constant warning time devices are used at crossings where there can be both fast and slow train speeds. The devices detect an approaching train and then measure its speed and wait to activate the lights and gates until the train is about 25 seconds away from the crossings. This avoids a problem with DC circuits in which a slow moving train may activate the lights and/or gates several minutes before the train reaches the crossing resulting in frustrating delays to motorists.
