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Railroad crossing signals in current use in America are made up of bells, flashing red lights and barrier gates. These warning devices are called "active warning devices." Many crossings with "active" warnings have only the flashing lights and bells. The bells are useful for warning pedestrians around a crossing; they generally can't be heard by motorists unless they are very close to the crossing. Wikipedia does not have an article with this exact name. ...

Active warning devices at railroad crossings are activated and de-activated by a device called a Track Circuit. The Track Circuit was invented by Dr. William Robinson and first installed on a railroad track in Pennsylvania in 1872. The Track Circuit is a loop and uses the rails as electric wires at low voltage. One rail is "positive" while the other is "negative." The original Track Circuit was Direct Current (DC) and DC Track Circuits are still used all over America. Alternating Current (AC) Track Circuits were invented in the 20th century to allow for measurement of train speed and detection of train motion. Train detection in both DC and AC Track Circuits occurs when the train's wheels, which are solid steel, cause a short, called a shunt, when they contact both rails of the Track Circuit. Track Circuits are often 1,320 feet in length (one quarter mile) on each side of the railroad crossing.

The flashing lights, bells and gates seen at railroad crossings in America have not changed significantly in over 50 years. There have only been small changes, such as the increase in the size of the lights, the addition of reflective tape to the gate arms and the substitution of LEDs for the old incandescent bulbs. Most flashing light displays, however, still have incandescent bulbs, which require a lot of power versus LED's.

In the 1990's, inventors, including Joe Pace of EVA Signal Corp. and I designed Strobe Lights into the display, replacing the old red flashing lights. Strobe Lights are much more visible during daylight and in fog, rain or snow. Also, Strobe Lights are highly energy efficient. That's why Strobe Lights are seen on all types of emergency vehicles and are increasingly being used on school buses and postal delivery vehicles. Although the federal government (FRA especially) and the railroad industry are well aware of the innovations in crossing warning devices and highly reliable replacements for the obsolete and dangerous Track Circuit, they have refused to adopt the new technologies. The reason is simple: money. Replacing the old and obsolete warning equipment and Track Circuits would cost billions. But, by not using new technologies, the government and railroads are sacrificing safety improvement and reduced deaths and injuries for money. The American People should be outraged, but very few citizens are fully aware of the situation.

Track Circuits malfunction all over America and on a daily basis. The most common malfunction is "false activation", where the warning devices at the crossing are turned on, but no train is present on the Track Circuit. The result is blocked highway traffic. Crossings have, in a number of documented instances, had flashing lights and lights / gates falsely activated for over 24 hours. Theoretically, a crossing could have a continuous activation of active warning devices as long as the power is on. Typical causes of "false activation" are (1) water on the track acting as a conductor of electricity and (2) a stuck relay. There are also other causes. The Texas Dept. of Public Safety gets over 300 calls a week to their 800 number from motorists reporting malfunctioning flashing lights and lights / gates. Almost all of the calls are for "false activation" of warning devices.

Much more insidious and dangerous is "failure of activation." If a train gets on the Track Circuit, but is not detected (no shunt happens), the active warning devices will NOT be activated. The train is moving toward the crossing, often at high speed, but the bells are not ringing, the lights are not flashing and the gates (if the crossing has them) will be in the "up" position. This exact scenario occurred on April 27, 2004, in Charlotte, Michigan. The result: a mother and her 15 year-old daughter were killed by an Amtrak train. Amtrak claimed immediately that the warning devices were working, but many witnesses near the crossing stated that the warning devices were OFF at the time of the crash. The most common cause of "failure of activation" is rust on the rails. Rust (iron oxide) will not conduct electricity and, therefore, will inhibit the "shunt." No "shunt" means no train detection! Many fatal and non-fatal crossing crashes have been caused by "failure of activation", or "late activation", where the train is not detected until it is very close to the crossing. But law enforcement investigators, ignorant of the Track Circuit and its operation, will blame the motorist. The railroads always blame the motorist in crossing crashes and law enforcement is trained by Operation Lifesaver, a "non-profit" tightly connected to the railroad industry, to believe crashes are always the driver's fault. The FRA, for its part, claims that "failure of activation" is extremely rare. Since they investigate less than 1 percent of the crashes, how would they know?

Former railroad employees have stated that the industry "hates" lights and lights / gates. The reason, again, is simple: money. A crossing with active warning devices requires maintenance, whereas a crossing with nothing but a "crossbuck sign" requires no maintenance, probably for 20 years or more. In a 1999 trial in Missouri, a Union Pacific official admitted that "lights and gates can reduce the chance of a collision by 90 percent." Yet, the vast majority of crossings in America do not have lights and gates. Railroads routinely claim a crossing with active warning devices costs them "between $3,000 and $5,000 a year to maintain."

Most U.S. railroad crossings have nothing but an "X" shaped "crossbuck sign" that says "railroad crossing." These crossings are called "passive" and they account for a high percentage of crashes, injuries and deaths. They are most often found in rural areas where sight obstructions, such as trees, bushes, weeds and embankments, hide trains from the view of motorists.