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RAIL TRANSIT TRACK INSPECTION PRACTICES In 2012, the number of transit rider trips in the United States reached a record 10.5 billion; according to APTA, almost half of those trips, 4.7 billion, were on transit-rail systems. Each one of those trips presents inherent risks because of the nature of the activityâlarge vehicles in motion. In order to minimize these risks, each agency must develop and adhere to inspection criteria or standards. Generally, a select few individuals in each transit agency develop and implement safety standards for the inspection and maintenance of track, vehicles, stations, signals, bridges, etc. Both FRA and APTA have developed track and vehicle inspec- tion standards which may or may not be applicable to the various transit agencies because of significant differences in systemsâ specifications and equipment. SUMMARY The purpose of this synthesis was to document for the rail transportation industry common safety and inspection standards and maintenance practices, based on the various rail system types. There are several modes of rail transit, including light rail, street car/trolley, heavy rail, and commuter rail; and each requires different specific safety, inspection, and maintenance standards. Track and gage differences among 19th century freight and passenger railroads in Canada and various regions of the United States caused increasing difficulties as long-distance transportation and shipping increased; so by the 1880s, the North American freight rail industry had standardized track design to permit the interchange of rail equipment. Consequently, there is one set of Track Safety Standards for freight railroads, as published and enforced by the FRA; but no âone size fits allâ set of standards is possible for passenger rail transit agencies. This synthesis summarizes state-of-the-practice information on track inspection and mainte- nance standards and recommended safety practices, in an effort to assist all transit agencies in the development of their own set of track safety standards and, more importantly, maintenance standards. Since many transit agencies are not part of the national railroad system, and therefore not governed by federal inspection or maintenance practices, each agency must establish its own maintenance program to ensure that passengers are transported in a safe and reliable manner. Each transit agency has unique operating characteristics, such as vehicle loading, wheel and axle configuration, capacity, suspension system, types of track, right-of-way clearance,
2 and gage; and a variety of propulsion methods (self-propelled, locomotive-hauled, diesel, electric, etc.). All share the same basic principle of flanged steel wheels running on fixed steel rails, and the geometry of the tracks is generally similar; however, minimum horizontal and vertical curve radii vary significantly, and many systems employ unique special track work designs, such as flange-bearing frogs, tongue and mate switches, and restraining rails. Each rail transit authority must develop its own criteria based upon these components. For this synthesis, a sample of rail transit properties across the United States was asked to complete a detailed questionnaire con- cerning track inspection and maintenance practices. Despite the differences in some responses, one tenet learned through survey response ran throughout: that the primary responsibil- ity of each agency or transit authority is passenger safety. The questionnaire and additional interviews revealed significant differences in track inspection and maintenance policies among the transit agencies surveyed. Some differ- ences are the result of variations in wheel diameter and pro- file, back-to-back dimensions, flange width and depth, etc.; or differences among types of rail, methods of rail attachment (cut spikes, direct fixation, etc.), and track gage and geometry. For example, the distance between axles and wheel sets deter- mines the minimum radius of the curves that the vehicle can negotiate. The amount of super elevation unbalance assigned to the curves and adjoining spiral lengths affects passenger ride comfort and limits the maximum permissible operating speed. The frequency of safety inspections and the standards for track maintenance that each agency uses must be tailored to these characteristics. As a result, personnel training varies significantly as well. However, all respondents reported that proper track maintenance is essential to passenger safety. To obtain information on current practices, a questionnaire was developed regarding the maintenance and ins pection of the track structure. Of the 35 agencies surveyed, 29 agencies responded for an 83% response rate. As the agenciesâ standards are confidential and therefore something of a sensitive topic, many agencies requested anonymity, and this report is respectful of their requests. Survey information has been limited to those involved in the preparation of this synthesis. According to the survey responses, the average age of the 29 agencies is 45 years. Agen- cies using electric traction power systems are evenly split between third-rail and overhead line (catenary). There is also an even split in the application of Track Safety Standards, FRA, or APTA. The majority of the agencies (69%) responded that they are not regulated by the FRA; a few stated that a portion of their system is regulated by the FRA. A third of the respon- dents (34%) stated they do not have a CWR (continuous welded rail) plan. The results of the survey are summarized in the matrix and bar graphs. In addition, seven transit supervisors provided answers to more specific and intuitive ques- tions about their philosophies pertaining to track maintenance. Case examples of three heavy rail agencies and one light rail agency offer more detailed information. Based on information collected for this synthesis, issues of training and certification, geometry testing standards, the wheel-to-rail interface, and procurement practices are suggested for future study.
