Requirements

The system will provide rail traffic information to emergency personnel for routing of emergency vehicles. It will need to provide this information in a variety of formats as the device which will access the information will have varying abilities. Additionally, the conditions under which the system will be used will vary by user.

The primary information being conveyed in all cases is whether a railroad grade crossing is occupied by a train (i.e. blocking road traffic). If so, then the estimated delay before the crossing becomes passable again is displayed. If the crossing is not occupied, then the estimated time until rail crossing occupation occurs is displayed. In addition, if a crossing is blocked the estimated time until rail crossing occupation is zero which logically follows. Likewise, if the crossing is not blocked, then the estimated delay is reported as zero.

This information can then be used by the emergency services personnel to appropriately route the vehicle to minimize transportation to or from the scene of an ermergency. It may turn out that it is faster for an emergency vehicle to travel to a crossing which is farther from their destination even if that crossing is currently occupied by a train if it is determined that by the time they reach the farther crossing the train is expected to have cleared the crossing. The closer crossing may be expected to be blocked by the time the emergency vehicle can reach it, and would therefore be delayed by the amount of time it would take for the train to entirely pass the crossing. The determination of which crossing to route the emergency vehicle is left up to the user of the system.

The time lost at crossings can be substantial as trains can be very long in length, and in most populated areas lower speed limits are imposed on train traffic to reduce the probability of a catastrophic derailment accident. Combined, these two factors can create a delay which is unacceptable for emergency responses. Additionally, if a vehicle is rerouted to another crossing behind the path of the current train, another train following the first may block it before the emergency vehicle can reach it. In this case, it may actually be beneficial for the emergency vehicle to simply wait for the crossing to be cleared by the current train.

Currently, train location is determined by an AC or DC circuited track. This type of indication does only conveys that a train is currently on that section of track (which may be of substantial length). Along with the train speed limit in that area (or maximum speed limit imposed on the train due to physical limitations or by legal regulations from hazardous payloads, and the length of the train, the system will be able to give an estimated time for the train to traverse a section of track. Future enhancements to the system could be included as new technologies are adopted by railways. Currently some railways are begining to use GPS location on trains. The railway uses the greater accuracy of the GPS units for better planning while relying on old hardware based systems for safety critical tasks. Additionally, integration of GPS location in emergency vehicles could provide the system with enough information to calculate and suggest best route options for the emergency vehicles based on profiles of the type of emergency service, what is considered to be a safe operating speed for the vehicle and the nature of the emergency being to which personnel is responding.