Perspective: Roadway Worker Warning System Alternative to PTC

By Kevin C. Smith

In the next five years, we should expect all railroad and rail transit operators to voluntarily adopt suitable forms of electronic train approach warning protection for work crews and lone workers working on or fouling railroad tracks. While current positive train control (PTC) regulation may address at least a part of this requirement, PTC will not be available on all track locations; therefore, an alternative method is required to augment the PTC worker protection approach.

One method of protection is to directly detect any train or rail vehicle as it enters an established work zone, regardless of dispatcher protection. The train operator will view an indication they are entering a track section where track workers will be present. Each crewman in the track gang, or even a lone worker walking down a track performing inspection duties, will receive an alert indicating the train's presence.

This method gives the track workers and the employee in charge (EIC) direct ability to protect their work zone. This would be supplemental to today's standard operating practices for train operators or central dispatchers.

Today, lone workers walking the track to inspect track integrity are essentially on their own in terms of protection. At best they are walking with a watchman with a single duty: watching out for oncoming train traffic. With today’s sensor and communication technology, it's possible to set up a zone of protection that follows the workers as they walk the track.

The protection zone will detect trains entering the limits of the zone and immediately send a warning alert to all workers within it. It's even possible to detect the location of the crew within the protected zone and automatically follow the workers as they move up or down the track, essentially forming a protection bubble around them. This virtual dynamic bubble will follow their movement and provide sufficient warning time so the track workers can safely clear the track. Such a robust and flexible worker protection product would be designed to be used as an overlay to the railroad's existing protection rules.

Easy setup, clear warnings

The detection zone virtual dynamic bubble should be easily set up by either the employee in charge of safety, or by the lone worker, and will inform the train's operator and train dispatch center of the activated protection zone and the location of the workers.  

When a train approaches the work zone, the train operator will receive either an on-board indication of the presence of the workers or will receive a lighted indication on the wayside. In either case, train operators will be provided with information that can save their co-workers lives.

Likewise, when the train is detected to enter the work zone, each equipped worker will receive a strobe light, haptic vibration and a high-pitched siren to indicate the train's approach. The alarm will be provided in sufficient time for the track worker to clear the track to a safe location.

The EIC or Roadway Worker in Charge (RWIC) would also receive the train detection alarm, as well as an alert if all workers in the protection zone haven't reached a point of safety. In that case, the EIC/RWIC is in control of train movement and will likely stop or slow the train until the last worker reports clear.   

Kevin C. Smith is senior vice president of global sales and marketing for Miller Ingenuity. The system described above has been developed and tested by Miller Ingenuity, and the company continues to collect user requirements and book orders for pilot systems to be evaluated by industry safety and operations experts. The product is expected be available for sale by the end of 2016.