R&M&A&S of communication based train control systems applied to Urban Rail Transportation — A way to improve city sustainability

The interrelation between dependability and sustainability has only been explored to a limited extent and this paper was written with the intent to advance this exploration with an example of how dependability supports sustainability for a particular type of complex engineered system. First the Dependability - Reliability, Maintainability, Availability, Safety (RAMS) - and Sustainability concepts are critically examined together with the theoretical arguments that support the relation between them. Then, this relation is illustrated for the Communication Based Train Control (CBTC) systems used to control Urban Rail Transportation /Transit (URT). A key factor that impacts city sustainability is transportation. One of the most efficient ways to move people around in a city is Urban Rail Networks, which typically form the backbone of the public transit system of any large metropolitan area. The CBTC, being the “brain” of an Urban Rail Network, controls how it operates and thus it has a direct impact on the efficiency and performance of the overall public transit system. Then the argument is made that Urban Railways controlled by a CBTC system lead to more sustainable transportation than the older traditional signaling systems, because of better efficiency, lower risk of accidents, reduction of environmental impact. The conclusion is that the more CBTC are refined to increase their RAMS, and the more such highly dependable CBTC are deployed, the more city sustainability is increased with positive effects on global sustainability. This is exemplified with a real case: Vancouver Skytrain which is a showcase of the compounded effects that an all-around de pendable system has on sustainability. Because the automation field covers railroad as well as roadway networks automation, the idea of generalizing the concept of automatic train control to the entire field is promising. That could be achieved by porting and adapting CBTC concepts from railway traffic to other modes of transportation, thus reducing the routine involvement of the human element in the control loop. Another more generic avenue of further research into how de pendability increases can contribute to sustainable development is the concept of cradle to grave product ownership. Based on this concept the users don't own products anymore, instead the manufacturer does own them, and users only “lease” products instead of buying them. This way the producers are intrinsically and economically motivated to build highly dependable products as a way to cut their ownership costs.