While railroad safety comes under the jurisdiction of national governments, which issue rules and policies for safety governance and enforcement, subways are usually governed by local public authorities, which in essence govern themselves.
Subway fares usually do not cover operating cost and, through subsidies, are kept at certain levels to maintain an affordable public transportation service. Subway and other city mass transit systems make city roads more accessible and reduce the pollution associated with urban automobile traffic.
Budget cuts that have become so common in many countries in recent years also affect mass transit systems. Preventive maintenance personnel and the upgrade of tracks, signals and rolling stock are the first to be affected. The controlling authorities are often unwilling or unable to enforce their own regulatory procedures on a rapid transit system abandoned by government subsidies. Inevitably in such circumstances, a transportation accident with catastrophic loss of life during the budget cuts results in a public outcry demanding improvements in safety.
While it is recognized that great variation exists in the design, construction and age of the physical facilities of the rapid transit properties in Canada, the United States and other countries, certain standard maintenance functions must be carried out to keep operating track, aerial and underground structures, passenger stations and related facilities in the safest possible condition.
Subway Operation and Maintenance
Subways differ from railroads in several basic ways:
- most subways run underground in tunnels
- subways run on electricity rather than diesel or steam (although there are also some electrical trains)
- subways run much more frequently than railroad trains
- graffiti removal is a major problem.
These factors influence the degree of risk for subway train operators and maintenance crews.
Collisions between subway trains on the same track and with maintenance crews on the track are a serious problem. These collisions are controlled by proper scheduling, central communications systems to alert subway train operators of problems and signal light systems indicating when operators can proceed safely. Breakdowns in these control procedures resulting in collisions can occur due to radio communication problems, broken or improperly placed signal lights that do not give operators adequate time to stop and fatigue problems from shift work and excessive overtime, resulting in inattention.
Maintenance crews patrol the subway tracks doing repairs to tracks, signal lights and other equipment, picking up rubbish and performing other duties. They face electrical hazards from the third rail carrying the electricity to operate the subways, fire and smoke hazards from burning rubbish and possible electrical fires, inhalation hazards from steel dust and other particulates in the air from the subway wheels and rails and the hazard of being hit by subway cars. Floods in subways can also create electrical shock and fire hazards. Because of the nature of subway tunnels, many of these hazardous situations are confined-space hazards.
Adequate ventilation to remove air contaminants, proper confined-space and other emergency procedures (e.g., evacuation procedures) for fires and floods and adequate communication procedures including radios and signal lights to notify subway train operators of the presence of maintenance crews on the tracks are essential to protect these crews. There should be frequent emergency spaces along subway walls or adequate space between tracks to allow maintenance crew members to avoid passing subway cars.
Graffiti removal from both the inside and outside of subway cars is a hazard in addition to regular painting and cleaning of cars. Graffiti removers often contained strong alkalis and hazardous solvents and can be a hazard both by skin contact and inhalation. Exterior graffiti removal is done by driving the cars through a car wash where the chemicals are sprayed on the exterior of the car. The chemicals are also applied by brushing and spraying inside subway cars. Applying hazardous graffiti removers inside cars could be a confined-space hazard.
Precautions include using the least toxic chemicals possible, proper respirator protection and other personal protective equipment and proper procedures to ensure that car operators know what chemicals are being used.