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To reduce the possibility of an public transportation accident, there are many  safety systems currently in place. Many more safety measures are being researched every day. However, on March 24, these safety systems did not fully work as a CTA Blue Line train jumped the track, came off of the platform, and crashed into an escalator leading into O’Hare Airport. A spokesman for Lutheran General Hospital said that seven people were treated for minor “whiplash-type” injuries. In total, 32 individuals were treated for injuries from this train accident. Whether or not the train was speeding or whether the safety systems were working probably is not yet clear yet. Either way, below are a few safety systems that were in place or should have been in place on Monday.

Automatic Braking Safety Systems

Unfortunately, the automatic emergency stop system was tripped before the train went through the end of the line barrier and the shock absorber at the end of the Blue Line. An example of an automatic braking safety system is the dead man’s switch, which automatically operates if the human operator becomes incapacitated. In this instance, the emergency brake system, may not have been applied as quickly as it should have. The automatic system should have stopped the train when the operator’s hand came off the controls.  Nonetheless, this public transportation safety system has been in place in many years in several countries and may have prevented several train accidents.

Photo from CTA

Positive Train Control

One of the goals of the Federal Railroad Administration is to create an integrated public transportation safety system for command, control, and communications. Positive train control (PTC) is “a system of functional requirements for monitoring and controlling train movements to provide increased safety.” The train would receive information about its location and where it is allowed to safely travel. The equipment would prevent unsafe movement. This could require GPS navigation and tracking. In an interview regarding the Blue Line accident, according to NTSB investigator Tim DePaepe, PTC is set to be installed on many railroads nationwide by next year.

Human Fatigue

Photo from CTA

One of the focuses of research is to develop safety systems to battle human fatigue. Currently, the team of federal safety experts is focused on the driver and any fatigue issues that caused this accident. The Federal Railroad Administration estimates more than one third of train crashes are caused by human factors, including fatigue. In the accident this week, a union representative said that the train operator had worked a lot of overtime recently and was extremely tired.

The NTSB (National Transportation Safety Board) has over 180 safety recommendations to address this problem. One example of a safety system is the medical oversight system. It  would recognize the dangers of sleep-related medical impairments, such as sleep apnea. Then it would incorporate mechanisms to identify affected public transportation workers. However, this it would not be an automatic public transportation safety system. It would require checking on humans instead of automatic brakes or system. But as long as human beings are involved, the human body is one of the key machines keeping our trains and buses running without accident. Safety systems must include making sure our operators are up to the shift.

De-Energizing Propulsion Power

Although not an issue in the current accident, in October 2013, an unoccupied train collided with an operating CTA train on the Blue Line. The accident injured 33 people. The NTSB recommended that “[d]e-energizing propulsion power and using an alternate brake setting could prevent unintended movement and ensure that a train that does move unintentionally would remain stopped at a mechanical train stop mechanism.”

The Transportation Research Board has put together at least seven models that could help with the develop of this safety system. One example of a public transportation safety system is through the motor overload condition that exists when “one of three relays in the propulsion’s system motor control box becomes energized.” (Demonstration of Artifical Intellignce Techonology for Transit Railcars Diagnostics, 2-12). When any of these relays become energized, the open contacts would disable the propulsion system.

Safety System Conclusion

Photo from CTA

In conclusion, safety systems are constantly being researched, but sometimes the funding is not there to implement them. However, when you step on a subway car, a bus, or an Amtrak train, you are assuming that they are taking every precaution necessary to keep you safe. In addition, they are to keep fellow riders safe. If this accident happened at rush hour, many bystanders who were heading up the escalators could have been injured or killed. Although the final details of what happened have not been released, the safety measures used in public transportation systems needs to be a focus.