CBTC/ERTMS/PTC Convergence

Abstract

A trend has recently emerged in re-signaling projects, especially in Europe, where infrastructure managers of large commuter rails are facing a dilemma: “should we install CBTC (Communication Based Train Control) or ERTMS (European Rail Traffic, Management System) — or both?” These commuter rails often span over a large territory, interfacing sometimes with the national network and have to cross through high-density traffic sections in crowded cities. This paper discusses this dilemma and the factors that contribute to the decision-making process of deploying a new signaling system. These factors, often captured early in the business case of the project, are more complex than the simple issues of a) high throughput capability (leaning toward CBTC) and b) interoperability needs (leaning toward ERTMS). Other factors are considered in the business case such as: operating needs of the railway including the regulation concepts, reducing the Life Cycle Cost of the system, the risk level that the owner is willing to carry, other high-profile national roll-out plans and special needs of key stakeholders. All of these different factors and parameters are discussed in this paper, and are illustrated by actual re-signaling projects in London, Paris, Madrid and Istanbul. The main characteristics of ERTMS and CBTC are presented with their pros and cons for these types of applications. The paper further discusses how the industry is reacting to this emerging trend. Are there any state-of-the-art signaling solutions from the suppliers that can fit these types of projects? The paper also gives an overview of the recent progress of the European Rail Industry in terms of research and development for future signaling systems in urban / suburban areas. Meanwhile, Positive Train Control (PTC) systems are being deployed in North America on class 1 railroads as mandated by the US congress, primarily as a means to increase safety. At the same time, some US rail transit agencies are adopting CBTC (albeit at a slow pace). The paper explores if there are any lessons from Europe related to CBTC/ERTMS convergence that could apply in North America related to CBTC/PTC convergence.