Federal Railway Administration Research Articles

Investigation of whistle noise impacting a residential subdivision

There have been complaints from residences within a residential subdivision in New Tecumseth, Ontario, of train noise from the Canadian Pacific Railway (CPR) line that passes directly east of the development. The complaints relate to sound levels experienced within the dwellings during train pass-bys, most notably from the use of whistles at the grade level crossing southeast of the site. Sound level measurements were completed to quantify the indoor and outdoor sound levels at several dwellings closest to the rail line. The measured sound levels were compared to predictions made using the Ministry of the Environment, Conservation and Parks (MECP) noise model Sound from Trains Environmental Analysis Method (STEAM). This investigation discusses shortfalls in STEAM, which resulted in the sound levels (from whistle noise) being under predicted at the dwellings. The study also compares the sound levels predicted using the Federal Railway Administration (FRA) horn noise model to those measured on site and predicted using STEAM.

Review: Death and Rebirth in a Southern City: Richmond’s Historic Cemeteries, by Ryan K. Smith

Review: <i>Death and Rebirth in a Southern City: Richmond’s Historic Cemeteries</i>, by Ryan K. Smith

Risk-based scheduling methodology for audit inspections of curves on high-speed mainline tracks

Agencies with safety oversight responsibilities of railroad tracks often perform walking audit inspections of tracks (also referred to as quality audits) to complement and oversee the regular inspections performed by the railway operator or maintenance manager. Traditionally, these audit inspections are scheduled based on the qualitative evaluation of the rail line by the inspectors, together with the available schedule of the inspector(s). This paper presents an approach to replace the current qualitative decision-making process for determining when and where to conduct audit inspections with a quantitative decision-making process. This quantitative process first establishes an acceptable level of risk in a given territory, and then taking into account the defect history and real-time track conditions, it schedules audit inspections based on those conditions. This risk-based scheduling methodology of audit inspections can be used by the safety oversight agencies and inspectors to monitor and “spot” check track conditions and provide oversight over the normal inspection process. The audit inspection’s frequency algorithm, presented in this paper, establishes the acceptable level of risk based on six years of Federal Railway Administration safety audit inspections data of the Amtrak North East Corridor. This methodology takes into account the track conditions in terms of the curve defect rate and optimizes the scheduling of audit inspections of mainline curves based on this defect condition. The risk-based curve audit inspections interval methodology outputs the required maximum curve audit inspections interval (time until next audit inspection or reinspection) while maintaining an accepted level of risk in the presence of real-time curve defect rates.

Driver injury severity study for truck involved accidents at highway-rail grade crossings in the United States

Although trucks only account for approximately 4% of all the vehicles based on the Federal Railway Administration (FRA) database, about 25% involved truck accidents happen at highway-rail grade crossings. This study applied an ordered probit model to explore the determinants of injury severity of truck drivers at highway-rail grade crossing in the United States. Given the importance of trucking to the economics of a country and the safety concerns posed by the trucks (as a result of their large size and weight making them difficult to control, maneuver, and stop), a comprehensive research on truck accidents is critical. Based on data analysis results, the strong effects of driver-, environmental-, weather- characteristics on the injury severities in truck accidents happened at highway-rail grade crossings are found. The findings reveal that better speed control for trucks will significantly reduce driver injury severity in accidents occurring at highway-rail grade crossings. In addition, several truck driver behavior characteristics (such as driving under influence of fatigue during peak hour) were found to be statistically significant predictors of high-level injury severity. Thus, education and enforcement targeted to truck drivers could facilitate safety improvements. Moreover, environmental factor (such as area type and roadway pavement) is found to be statistically significant. Truck drivers are more likely to have severe injury in open space area with low traffic volume compared with other areas. The bad weather and visibility condition is found to increase the probability of truck drivers’ high level injury severity.

The effect of time of day on driver's injury severity at highway-rail grade crossings in the United States

Based on the Federal Railway Administration (FRA) database, there were totally 25,945 highway-rail crossing crashes happened in the United States between 2002 and 2011. With an extensive research, analysis results showed that there were substantial differences by time of day for driver's injury severity at highway-rail grade crossings. However, there is no published study on time of day analysis of driver's injury given that a highway-rail grade crossing crash happens. This study applied ordered probit models to explore the determinants of injury severity for motor vehicle drivers at highway-rail grade crossings. The results show that motor vehicle driver's injury severity in highway-rail grade crossing crashes that happen during a.m. peak, p.m. peak, and p.m. off-peak is extremely higher than other time periods. However, speed control will significantly reduce driver's injury severity. In addition, crashes that happen during early morning, a.m. peak, and p.m. peak are more likely to be influenced by vehicle speed and train speed compared with other time periods. Paved highways will significantly help to reduce driver's injury severity at highway-rail grade crossings. Drivers during peak hours, early morning and p.m. off-peak are more likely to be influenced by unpaved roadway compared with other time periods.

저심도 터널과 인접한 방진벽의 지반진동 저감효과

본 논문에서는 계측자료와 해석방법의 조합에 의하여 지반진동을 평가하는 방법을 제시하였다. 평가방법의 기본개념은 FRA(Federal Railway Administration)에서 발간한 진동상세평가 매뉴얼에서 제시한 방법과 유사하나 구체적 평가방법은 다양한 유형의 방진벽의 진동저감 효과를 용이하게 평가할 수 있도록 수정되었다. 터널바닥에 작용하는 하중밀도(force density)는 해당선로의 차량 및 궤도조건을 잘 고려할 수 있는 차량-궤도 상호작용해석에 의하여 산정하였다. 지반진동의 전파유동성(transfer mobility) 2차원 지반진동해석을 통하여 평가하였다. 지반진동의 2차원 해석은 각 모델간의 상대비교에 있어서는 좋은 결과를 얻을 수 있으나 절대치 평가는 어렵다. 따라서 여기서는 사전에 계측된 자료와 해석결과의 비교를 통하여 실제 지반진동 전파특성을 반영할 수 있도록 계산된 전파유동성을 보완하였다. 정립된 진동평가방법을 적용하여 실제 진동민원문제가 크게 발생하였던 도시철도 저심도 터널구간을 대상으로 9가지 유형의 방진벽의 진동저감 효과를 분석하였다. This paper presents an assessment method of the ground vibration level with a combination of measured data and an analytic method. The basic concept of the method is similar to that in FRA(Federal Railway Administration) manual for detailed vibration analyses. However, going into detail, the assessment method was modified for a feasible evaluation of the vibration reduction effects of diverse types of wave barriers. The force density was evaluated in a vehicle-track interaction analysis and the transfer mobility of vibration was analyzed through a 2-D ground vibration analysis. The calculated 2-D transfer mobility was corrected to incorporate transfer characteristics of actual ground vibration by comparing the previously measured data and analysis results. Nine types of vibration reduction effects of wave barriers were analyzed on a shallow tunnel section of an urban railway where numerous civil complaints had actually been filed.

Difference in rural and urban driver-injury severities in highway–rail grade crossing accidents

Based on the Federal Railway Administration (FRA) database, there were 25,945 highway–rail crossing accidents in the United States between 2002 and 2011. With an extensive research, analysis results showed that there were substantial differences between rural and urban areas at highway–rail grade crossings. However, there is no published study specific on driver's injury severity at highway–rail grade crossings classified by area types. Using an ordered probit modelling approach, the study explores the determinants of driver-injury severity at rural highway–rail grade crossings compared with urban highway–rail grade crossings. The analysis found that motor vehicle driver's injury level at rural highway–rail grade crossing is extremely higher than urban area. Compared to collisions at urban area, collisions happened at rural area tend to result in more severe injuries. These crashes were more prevalent if vehicle drivers are driving at a high speed or the oncoming trains are high-speed. Moreover, highway–rail grade crossing accidents were more likely to occur at rural area without pavement and lighting.

The effect of age and gender on motor vehicle driver injury severity at highway-rail grade crossings in the United States

IntroductionBased on the Federal Railway Administration (FRA) database, there were 25,945 highway-rail crossing accidents in the United States between 2002 and 2011. With an extensive database of highway-rail grade crossing accidents in the United States from 2002 to 2011, estimation results showed that there were substantial differences across age/gender groups for driver's injury severity. MethodThe study applied an ordered probit model to explore the determinants of driver injury severity for motor vehicle drivers at highway-rail grade crossings. ResultsThe analysis found that there are important behavioral and physical differences between male and female drivers given a highway-rail grade crossing accident happened. Practical applicationsOlder drivers have higher fatality probabilities when driving in open space under passive control especially during bad weather condition. Younger male drivers are found to be more likely to have severe injuries at rush hour with high vehicle speed passing unpaved highway-rail grade crossings under passive control. Synthesizing these results led to the conclusion that the primary problem with young is risk-taking and lack of vehicle handling skills. The strength of older drivers lies in their aversion to risk, but physical degradation issues which result in longer reaction/perception times and degradation in vision and hearing often counterbalance this attribute.

Motor vehicle driver injury severity study under various traffic control at highway-rail grade crossings in the United States

IntroductionBased on the Federal Railway Administration (FRA) database, approximately 62% of the collisions at highway-rail crossings occurred at locations with active controls (gate and flashing lights), followed by passive controls (cross bucks and stop signs) with approximately 28% of accidents. MethodThe study applied an ordered probit model to explore the determinants of driver injury severity under various control measures at highway-rail grade crossing in the United States. ResultsThe analysis found that schedule factor (peak hour), visibility, motor vehicle speed, train speed, driver’s age, area type, traffic volume and highway pavement impact driver injury severity at both active and passive highway-rail crossings. Practical ApplicationsFor both active and passive control highway-rail grade crossings, speed control for both trains and vehicles will significantly reduce driver injury severity. However, the level of influence by vehicle speed and train speed at passive control is higher compared with active control. Paving highways at highway-rail grade crossings will also help to reduce driver injury severity at highway-rail crossing accidents.

Optimization of high speed EMU suspension parameters for vibration reduction

Various designs of high speed EMU (electric multiple units) operating at maximum speed of 400 km/h or above are under active development in many countries. Driving at such extreme high speed, the EMUs that are equipped with multiple power units and non articulated bogies normally experience severe level of vibration. Noting one of the primary design issues of the vertical EMU vibration, the present work tries an optimization of vehicle suspension system using ten degree of freedom analytical EMU model. The objective function for the work is consisted of the rail power spectral density (PSD), transfer function of car body, and frequency dependent weighting function which may represent human riding comfort. The transfer function is formulated using an autocorrelation of the model in frequency domain. For the enhanced reliability of the optimization work, both the US FRA (Federal Railway Administration) rail PSD and the actual rail PSD acquired from Kyeong-bu high speed rail in Korea on which the particular EMU will be driven are used. The well proven BFGS (Broyden-Fletcher-Goldfarb-Shanno) method is adopted for the optimization. The optimized design is verified using a commercial dynamic system simulation code at various operating conditions.

The use of micaceous iron oxide in longterm‐corrosion protection

If a weather‐beaten structural steelwork, protected by a full system of anticorrosive coatings, will show a lifetime of over 20 years without any maintenance during this time, we will speak of a ‘longterm Corrosion Protection.’ These 20 years often seem to be too long, but many case‐histories of structural steelworks over the whole of Europe, such as bridges, tankfarms, cranes etc. will prove it. By the way, the German Railway Administration foresees a major repainting of their objects only every 20 years, the Swiss Federal Railway Administration only after 25–30 years. The most parts of these protective coatings are pigmented with Micaceous Iron Oxide (MIO), a pigment with the highest life expectance.