Prevention of End-of-Track Collisions at Passenger Terminals via Positive Train Control

Abstract

A series of end-of-track collisions occurred in passenger terminals because of noncompliant actions from disengaged or inattentive engineers, resulting in significant property damage and casualties. Compared with other types of accidents, end-of-track collision has received much less attention in the prior research. To narrow this knowledge gap, this paper firstly analyzes the safety statistics of end-of-track collisions, then develops a fault tree analysis to understand the causes and contributing factors of end-of-track collisions. With the objective of mitigating this type of risk, this paper discusses the potential implementation of Positive Train Control (PTC) for the passenger terminal. This paper primarily focuses on the enforcement of the two most widely implemented systems, the Advanced Civil Speed Enforcement System (ACSES) and the Interoperable Electronic Train Management System (I-ETMS). For each implementation scenario, the Concept of Operations (ConOps) is proposed that depicts high-level system characteristics for the proposed PTC system enforcement at stub-end terminals. Ongoing work is being carried out by the authors to fully evaluate the cost-effectiveness and operational impacts of enforcing PTC in terminating tracks to prevent end-of-track collisions.

Prevention of End-of-Track Collisions in Passenger Terminals via Positive Train Control: Benefit-Cost Analysis and Operational Impact Assessment

“…A train moving under the maximum speed could still cause an end-of-track collision, which cannot be prevented by the ATC alone. The proposed solution from Zhang et al is to install additional transponder sets at the second zone on platform tracks (Figure 1 a ) ( 2 ). The first transponder set (T1) in Zone 2 activates the ACSES system that is able to provide positive train stop (PTS) before the end of the platform track.…”

“…If train movement is compliant with operation rules and tolerable braking distance exists, the train will still be under the engineer’s operation. Once the train is over-speeding or has inadequate stopping distance, the ACSES system will release a warning or even a penalty brake that will slow the train down and eventually safely stop it short of the end of the terminating track ( 2 ). Interested readers can refer to Zhang et al for more details ( 2 ).…”

“…After the investigation of these two recent, severe end-of-track collisions, the National Transportation Safety Board (NTSB) recommended intercity passenger and commuter railroads to implement technology to stop trains before reaching the end of tracks ( 1 ). The previous study projected a Positive Train Control (PTC) system-involved strategy to mitigate end-of-track collision risk and enhance the safety level of passenger terminals ( 2 ). A concept of operations (ConOps) was developed to outline the proposed plans to implement two of the most widely used PTC types, namely the Advanced Civil Speed Enforcement System (ACSES) and the Interoperable Electronic Train Management System (I-ETMS).…”

“…A concept of operations (ConOps) was developed to outline the proposed plans to implement two of the most widely used PTC types, namely the Advanced Civil Speed Enforcement System (ACSES) and the Interoperable Electronic Train Management System (I-ETMS). In sum, Zhang et al proposed the installation of transponders in ACSES-type terminals and conduct track mapping and wayside interface unit (WIU) installation in I-ETMS-type terminals ( 2 ). As an ongoing project that aims to provide a comprehensive assessment of the proposed ConOps, this study mainly conducts an ex-ante evaluation of the previously proposed PTC implementation at passenger terminal stations along three lines of inquiry:…”

“…This paper is organized as follows. First, this paper provides a brief review of the ConOps for PTC enforcement at terminal tracks proposed by Zhang et al ( 2 ). Second, nationwide safety benefits and costs with the PTC enforcement at stub-end terminals are estimated and compared against each other with two metrics: net present value (NPV) and benefit-cost ratio.…”