Level crossing

The term level crossing (also called a railroad crossing, railway crossing, or grade crossing) is a crossing on one level ("at-grade intersection") — without recourse to a bridge or tunnel — used to describe the crossing of a railway line by a road, path, or other railroad. It also applies when a light rail line with separate right-of-way (or a reserved track tramway) crosses a road; the term "metro" usually means by definition that there are no level crossings (i.e., that the system is grade-separated).

Safety

The original design for a level crossing consisted of a flagman in a nearby booth who would, on the approach of a train, race out with a stop sign or red lantern and (attempt to) stop all traffic and clear the tracks. Manual or electrical closable gates which barricaded the roadway were later introduced. The gates were intended to be a complete barrier against intrusion of any road traffic onto the railway. In the early days of the railways much road traffic was horsedrawn or included livestock. It was thus neccessary to provide a real barrier.

With the appearance of motor vehicles, this barrier became less and less effective and the need for a barrier to livestock diminished dramatically. Many countries therefore substituted the gated crossings with much less strong, but highly visible barriers and relied upon road users following the associated warning signals to stop.

In many countries, on less important roads and railway lines, level crossings are often "open" or "uncontrolled" but these have warning lights or bells to warn of approaching trains. Ungated crossings represent a safety issue; many accidents have occurred due to failure to notice or obey the warning. Railways in the United States are adding reflectors to the side of each train car to help prevent accidents at level crossings. In some countries, such as Ireland, instead of an open crossing there may be manually operated gates, which the motorist must open and close. These too have significant risks, as they are unsafe to use without possessing a knowledge of the train timetable: motorists may be instructed to telephone the railway signaller, but may not always do so.

The consensus in contemporary railway design is to avoid the use of level crossings. The director of rail safety at the UK Railway Inspectorate commented in 2004 that "the use of level crossings contributes the greatest potential for catastrophic risk on the railways." Eighteen people were killed in the UK on level crossings in the 2003-4 period. Bridges and tunnels are favoured, and there is a commitment on the part of UK rail authorities not to build new level crossings, and to reduce the number of existing level crossings from the present 8,200. The cost of making significant reductions, other than by simply closing the crossings, would be substantial, and a number of commentators argue that the money could be better spent. Some 6,500 of the 8,200 crossings are user-worked crossings or footpaths, with very low usage. The removal of crossings also frequently improves train performance as most crossings have strict and low speed limits enforced on them to protect the user.

A level crossing on China National Highway 109 in Beijing, China.

In November 2004 there were two major accidents on UK level crossings: one involved a car driver suspected of being a suicide, who caused the death of seven people (see Ufton Nervet rail crash); another involving a train carrying 50 school children resulted in no fatalities but a number of injuries. These incidents have increased efforts to review the placing of level crossings and to eliminate them where this is practicable. In the UK it has also been suggested that cameras similar to the type used to detect drivers who run traffic lights be deployed at level crossings, and that penalties for ignoring signals should be much more severe.

Third rail systems may also have level crossings: there is a gap in the third rail over the level crossing, but in spite of that the power supply is not interrupted since trains have current collectors in the front and rear cars; however, care must be taken that a current or voltage gap is not created between the two ends. At railway stations a pedestrian level crossing is sometimes provided to allow passengers to reach other platforms in the absence of an underpass or bridge.

Crossings around the world

Australia

In Melbourne, Australia, there are several level crossings where the train tracks cross tram tracks on the road. These crossings require trains to travel very slowly to avoid tangling the overhead cables. Australian railroading generally follows United States practice, and has increasingly been employing American-made crossing warning equipment, such as grade crossing predictors, which attempt to provide a consistent amount of warning time for a trains of widely varying speeds.

One recent innovation in Australia is to provide crossbucks with flashing yellow lights at a distance from the level crossing itself, particularly where there are curves and visibility problems.

New Zealand

In parts of rural New Zealand, roads and railways share the same road space when crossing a river; the rails are run in the road and both motorists and the train driver must ensure that the bridge is clear, end to end, before starting to cross. There are several examples in South Island including the Taieri Gorge line.

Southeast Asia

A manually-operated level crossing in India.

Level crossings in China, Thailand, and Malaysia are still largely manually-operated, wherein the barriers are lowered using a manual switch when trains approach. A significant number of crossings are without barriers.

United Kingdom

In the United Kingdom, all major crossings were normally situated within easy viewing distance of a signal box, and usually directly adjacent to the signal box. This ensured that the signalman can verify the road ahead is clear before allowing a train to cross the section of track involved. Many of the gated crossings have been replaced with lifting barriers which are easier to mechanise. "Full barriers" consist of barriers each side of the track which block the full width of the road and "half barriers" consist of a single arm each side of the road which block only the oncoming traffic. Half barriers were considered to have an advantage as motorists are less likely to be stranded on the crossing and unable to exit but cases where impatient motorists have driven around the barriers have raised safety concerns. Modern cameras are now often used at crossings to allow the human operator to be some distance from the crossing. On lightly used railways many crossings are sited next to station stops or other stopping points and crew operated. The guard pushes a plunger on a control box and the barriers are lowered. Once lowered an indicator light permits the driver to proceed if the crossing ahead of is clear. After the train has cleared the crossing automatic control equipment raises the barriers.

To ensure that the barriers are noticed and draw attention larger crossings are fitted with a ringing warning bell or siren, and with traffic lights. Each crossing point also has a telephone which connects to the local signalbox so that in the case of an emergency the signalman's attention can be drawn promptly to the hazard and action can be taken. Some smaller crossings, particularly obscure pedestrian crossings on low speed parts of branchlines consist of nothing but a warning sign and raised pathway across the track itself.

The use of pedestrian crossings at stations is now rare, although historically it was common that passengers walked across the line between platforms on branch lines. With a few exceptions such as Carmarthen railway station the remaining examples occur only on heritage railways.

United States

In the United States, and in countries following U.S. practices, a train must have a bright headlight and ditch lights, a working bell, and a whistle or horn that must be sounded as the train approaches the crossing. Some American cities, in the interest of noise abatement, have passed laws prohibiting the sounding of bells and whistles; however, their ability to enforce such rules is debatable. In December of 2003, The U.S. Federal Railroad Administration published regulations that would create areas where train horns could be silenced, provided that certain safety measures were put in place. Additional information can be found at the FRA website and following the page link under "Train horn rule." Implementation of the new "Quiet Zone" Final Rule was delayed repeatedly, but finally implemented in the summer of 2005.

File:Rr crossing.jpg

An example of a typical rail crossing in the United States.

All crossings in the United States are required to be marked by at least a crossbuck; Most crossings that intersect rural roads have this setup. As traffic on the road crossing or the rail crossing increases, safety features are ramped up accordingly. More densely populated crossings have alternately flashing red lights to warn motorists, and a bell to warn pedestrians. Additional safety is attained through boomgates that block motorists approach to the tracks when activated. Increasingly, crossings are being fitted with so-called four-quadrant gates.

A handful of level crossings still use a wigwag signal, which was developed in the early 1900s by the Pacific Electric Railway interurban system in the Los Angeles region to protect its many level crossings. Though now considered to be antique, around 100 such signals are still in use, almost all on branch lines. By law, these signals must be replaced by the now-standard alternating red lights when they are retired.

A track that will run high-speed trains in excess of 120 mph (193 km/h) is being tested in Illinois between Chicago and St. Louis, Missouri. Here, due to the high speed of the trains, gates that totally prevent road traffic from reaching the tracks are mandatory on all level crossings, and steel mesh nets are being tested on the busier crossings to further prevent collisions. These are already in place in Southeastern Connecticut along Amtrak's Northeast Corridor; the rest of the Northeast Corridor is grade-separated.

Accidents

Hixon rail crash — 1968
Fox River Grove level crossing accident — 1995
Bourbonnais train accident — 1999
Gerogery level crossing accident — 2001
Ufton Nervet rail crash — 2004
Glendale train crash — 2005
Polgahawela level crossing collision, Sri Lanka — 2005: a bus tries to beat the train at a level crossing; at least 35 people are killed.
Johannesburg level crossing accident — 2005: 9 killed.

External links

Cost-effective Systems for Railway Level-Crossing Protection from the UN Economic and Social Commission for Asia and the Pacific
Train horn rule at the US Federal Railroad Administration
Fatal example of crossings danger - News story from the BBC on a 2004 accident in which 7 people died.
Level Crossing Strategy Council - New South Wales, Australia.