Examining Intercity Rail Passenger Station Access Patterns

Travel on intercity passenger rail is growing in popularity across the U.S. Amtrak, the nation’s intercity passenger rail operator, reported a steady growth in ridership over the last decade; for the 12-month period ending in September 2011, Amtrak carried more than 30 million passengers, a first in the company’s 40-year history. This growth has resulted in widespread interest in developing new intercity passenger rail services or improving existing services with new station facilities and other investments. An issue of interest to the rail planning and policy community revolves around station access patterns, and there are many questions that remain unanswered on this subject. For this paper, these questions include: What is the mode share for passenger trips to and from the rail station? How far do passengers travel to access rail services? Has the market area for intercity passenger rail expanded with increasing ridership, or has the market area remained unchanged during this recent period of growth? Using data obtained from on-board surveys of existing Amtrak passengers in Michigan and Wisconsin, USA, this paper examines the evolving nature of rail passenger station access patterns over the last decade. Specifically, patterns in the overall station access trip mode split, the passengers’ self-reported travel time to and from the rail station, and the spatial distribution of passenger home residential zip codes relative to the rail station are analyzed. Analysis shows that 50 percent of rail passengers reside between 8 and 20 miles from a rail station, depending on the route, and that the market area for selected routes has expanded in recent years. Rail planners can use the findings from this paper to develop new station facility designs or to correct issues that may be present at existing stations. The findings of this paper can also be used to guide the deployment of marketing and promotion of rail services to residents within the “catchment area” of a station.

Driver Behavior Analysis Using Vehicle Safety Systems’ Field Operational Test Data

The United States Department of Transportation’s (US DOT) Research and Innovative Technology Administration’s John A. Volpe National Transportation Systems Center (Volpe Center), under the direction of the US DOT Federal Railroad Administration (FRA) Office of Research and Development (R&D), is leveraging the National Highway Traffic Safety Administration (NHTSA) sponsored Integrated Vehicle Based Safety System (IVBSS) Light Vehicle (LV) Field Operational Test (FOT) to collect and analyze drivers’ activities at or on approach to highway-rail grade crossings. Grade crossings in Michigan, Indiana, and Ohio were cross-referenced with IVBSS LV FOT research vehicle location to identify the time research vehicles were present at a crossing. The IVBSS LV FOT included 108 participants that took a total of 22,656 trips. Of the 22,656 total trips, 3,137 trips included a total of 4,215 grade crossing events. The analysis was based of drivers’ activities at the 4,215 grade crossing events. Both looking behavior and distractions did not significantly differ based on gender. However when analyzed per age-group, younger drivers (between 20 to 30 years old) were significantly more likely to be distracted than middle-aged drivers (between 40 to 50 years old) or older drivers (between 60 to 70 years old). For looking behavior, the data revealed that older drivers are more likely to look at least one way at or on approach to highway-rail crossing (43.8 percent exhibited this behavior) than either middle-aged drivers (35.0 percent exhibited this behavior) or younger drivers (25.3 percent exhibited this behavior).

Crippling Test of a Budd Pioneer Passenger Car

This research program was sponsored by the Federal Railroad Administration (FRA) Office of Research and Development in support of the advancement of improved safety standards for passenger rail vehicles. FRA and the Volpe National Transportation Systems Center (Volpe Center) have conducted a research program to develop alternative methods for demonstrating occupied volume integrity (OVI) of passenger rail cars using a combination of testing and analysis. Previous publications have addressed the planning and progress of a series of tests intended to examine the collision load path through the occupant volume of passenger cars equipped with crash energy management (CEM) systems. This program has included an elastic 800-kip buff strength test, two quasi-static tests that loaded a passenger car to its ultimate (crippling) capacity, and corresponding finite element (FE) analyses of each test. This paper discusses the two crippling tests and the companion FE analyses. One alternative method for evaluating OVI moves the applied loads from the line of draft to the collision load path. This alternative methodology also permits a combination of testing and analysis to be used to demonstrate the car’s OVI, in contrast to the conventional methodology (as prescribed in existing FRA regulations) which only permits testing. The alternative methodology was adopted as the recommendations developed by the Railroad Safety Advisory Committee’s (RSAC) Engineering Task Force (ETF) in its “Technical Criteria and Procedures for Evaluating the Crashworthiness and Occupant Protection Performance of Alternatively-Designed Passenger Rail Equipment for Use in Tier I Service.” The research program was undertaken to verify the efficacy of using a combination of elastic testing and plastic analysis to evaluate the OVI of a passenger car loaded along its collision load path as prescribed in the ETF report. Earlier in this research program an elastic test of a Budd Pioneer car was used to validate an FE model of the car, per the ETF’s procedures. This model was then modified to reflect the condition of the car in its crippling test configuration. The model was used to simulate the crippling behavior of the car, following the ETF’s procedures. Two Pioneer cars were then tested to crippling to provide additional data to validate the FE model and the proposed alternative OVI evaluation. Because the test cars used in this research program were equipped with CEM systems, the alternative evaluation loads were placed at the locations where the energy-absorbing components attached to the occupant volume. During both crippling tests, loads were measured at each energy-absorber support location on the live and restrained ends of the car. Additional instrumentation used in the second crippling test included strain gages on the major longitudinal structural members, displacement transducers at each load location, and vertical, lateral, and longitudinal displacement transducers on the underframe of the car. The results of the FE analysis compare favorably with the results of the crippling tests. In particular, the crippling loads are consistent between the tests and analysis: crippling loads for the first and second cars tested were 1.15 and 1.19 million pounds respectively, and the pre-test FEA estimated a crippling load of 1.19 million pounds. The research program has established a technical basis for the alternative OVI requirements and methodology.

Estimation of Track Irregularity Based on Genetic Algorithm and Unscented Kalman Filtering

Track irregularity is the main excitation source of wheel-track interaction. Due to the difference of speed, axle load and suspension parameters between track inspection train and the operating trains, the data acquired from the inspection car cannot completely reflect the real status of track irregularity when the operating trains go through the rail. In this paper, an estimation method of track irregularity is proposed using genetic algorithm and Unscented Kalman Filtering. Firstly, a vehicle-track vertical coupling model is established, in which the high-speed vehicle is assumed as a rigid body with two layers of spring and damping system and the track is viewed as an elastic system with three layers. Then, the static track irregularity is estimated by genetic algorithm using the vibration data of vehicle and dynamic track irregularity which are acquired from the inspection car. And the dynamic responses of vehicle and track can be solved if the static track irregularity is known. So combining with vehicle track coupling model of different operating train, the potential dynamic track irregularity is solved by simulation, which the operating train could goes through. To get a better estimation result, Unscented Kalman Filtering (UKF) algorithm is employed to optimize the dynamic responses of rail using measurement data of vehicle vibration. The simulation results show that the estimated static track irregularity and the vibration responses of vehicle track system can go well with the true value. It can be realized to estimate the real rail status when different trains go through the rail by this method.

Monitoring the Stress Free Temperature of a Complex Segment of Track

A 1.25 km segment of a heavy haul coal line was instrumented with Rail Stress Monitors (RSM) [1–7] and monitored throughout a winter-summer swing in ambient conditions. The track segment included a reverse curve spanning elevated, at-grade, and tunnel conditions that transitioned to a turnout. Natural events along with track maintenance activity punctuated the seasonal shifts in Stress Free Temperature (SFT).

Improving Casting Integrity Through the Use of Simulation Software and Advanced Inspection Methods

Casting integrity is essential for providing components that meet design criteria for strength and fatigue performance. As the leading method of manufacturing metal components in the rail industry, maintaining quality and consistency is a continuing struggle for car owners and builders. Internal shrinkage and voids due to insufficient metal flow are issues commonly found in casting molds which are not designed or utilized properly. Using casting simulation software, potential issues can be discovered upfront and robust mold designs can be created that offer a tolerance for the variance or variations in casting conditions that are present in the real world. Strato, Inc. has extensively studied the effectiveness of these simulations in foundries through advanced inspection techniques. It is evident that casting simulations can not only locate, but also explain shrinkage cavities and voids through material density plots and inspection of directional solidification via critical fraction solid time plots. This approach is markedly more efficient than the traditional trial and error method, where mold makers rely on experience and destructive testing to develop acceptable mold designs. With recent advances in simulation software, the labor and time-intensive ways of the past have been supplanted by a more scientific approach to the problem. Understanding the fluid dynamics and thermodynamics of the casting process provides a means of creating a stable, repeatable final product. This higher quality final product can be delivered faster to the customer and at a far less expense by identifying problem areas prior to the tooling and sampling processes. Case-studies explored by the Strato engineering team suggest that using this software decreases the fallout rate.

RTCONTACT: An Efficient Wheel-Rail Contact Algorithm for Real-Time Dynamic Simulations

Determination of contact forces exchanged between wheel and rail is one of the most important topics in railway dynamics. Recent studies are oriented to improve the existing contact methods in terms of computational efficiency on one side and on the other side to develop more complex and precise representation of the contact problem. This work shows some new results of the contact code developed at Politecnico di Torino identified as RTCONTACT; this code, which is an improvement of the CONPOL algorithm, is the result of long term activities, early versions were used in conjunction with MBS codes or in Matlab® environment to simulate vehicle behaviour. The code has been improved also using experimental tests performed on a scaled roller-rig. More recently the contact model was improved in order to obtain a higher computational efficiency that is a required for the use inside of a Real Time process. Benefit of a Real Time contact algorithm is the possibility to use complex simulation models in diagnostic or control systems in order to improve their performances. This work shows several comparisons of the RTCONTACT contact code respect commercial codes, standards and benchmark results.

Laser-Based Measurement of Over Dimensional Freight Rail Shipments

In pursuit of improved safety, Norfolk Southern Corp. (NS) has partnered with Amberg Technologies to explore the potential benefits of a laser-based measurement system for measuring over dimensional freight rail shipments. Shipments that do not fall within a standard geometric envelope, denoted as Plate B in the Association of American Railroads (AAR) Open Top Loading Rules [1], are considered to be over dimensional, or High-Wide Loads (HWLs). Extending beyond the limits of the Plate B diagram, these loads are not permitted in unrestricted interchange service. Instead, they must be measured both at points of origin and at interchange points. For US Class I Railroads, the de facto method for measuring HWLs requires mechanical personnel to either climb on the equipment or use a ladder and physically measure the overall height and width of the load. Using a tape measure, plumb line, and 6-foot level, car inspectors, or carmen, must often make multiple measurements to determine the height or width of a critical point on the load. The summation of these measurements can be subject to mathematical human error. In addition to the inherent limitations with regards to accuracy and efficiency, this method of measurement presents considerable safety challenges. The objective of the project was to develop a portable, cost-effective and accurate measurement system to improve the day-to-day operational process of measuring HWLs and reduce human exposure to railyard hazards. Norfolk Southern worked closely with Amberg Technologies to provide a clear overview of the current measuring methods, requirements, challenges and risks associated with HWLs. Amberg then developed a prototype system (with patent pending) and successful tests have been completed at both a point of origin for NS shipments and at a location where HWLs are received at interchange. The measuring system consists of a tripod mounted laser, a specially designed track reference target (TRT) and software designed specifically for HWL measurements. The system allows car inspectors to take measurements from a safe, strategic location away from the car. As a result, this system eliminates the need to climb on the equipment or a ladder and greatly reduces the amount of time spent on and around live tracks. In addition, initial tests indicate that this technology reduces the labor time required to measure HWLs by as much as one half while improving measurement accuracy. These tests have demonstrated that a laser-based system has the potential to greatly improve the safety, efficiency and accuracy associated with measuring HWLs.

The Use of Packet-Switched vs. Circuit-Switched Networks for Data Transport in a Public Transit Environment

Ethernet has become the de-facto standard for providing data transport not just throughout the internet but for numerous private and industrial networks. Prior to Ethernet’s dominance, circuit-switched networks (or time-division multiplexed networks like SONET) were popular choices for applications that required flexible and reliable data transport. Over the past 10 years, packet-switched networks in general (and Ethernet in particular) have usurped the role formerly played by these circuit-switched networks but is this a good development given that not all applications that require data transport are created equal? In the public transit environment, data transport networks are often used for mission critical applications that directly support revenue service such as signaling and train control and are increasingly based upon packet-switched networks. This paper will explore the current trend of using packet-switched as opposed to circuit-switched networks in the context of providing data transport for rail-based public transit agencies and, after examining five case studies, draw conclusions that are relevant for public transit agencies.

Sequence Optimization for Timetabling High Frequency Passenger Trains

Recently, Harrod has revealed that the occupancy constraints are not sufficient to timetable rail traffic. This insufficiency occurs when opposite movements of trains share the same route. In this paper, we propose a quick algorithm that considers overtaking and opposite train’s movements. This algorithm builds a train timetable from a proposed sequence of trains. It is based on an elementary model of an invariant resource sharing system. The algorithm is proposed in order to extend the genetic algorithm that calculates the sequence of trains for maximizing the frequency of passenger’s train.