Transportation Research Record: Journal of the Transportation Research Board

Journal Information
ISSN / EISSN: 03611981 / 21694052
Published by: SAGE Publications
Total articles ≅ 22,168

Latest articles in this journal

Transportation Research Record: Journal of the Transportation Research Board; https://doi.org/10.1177/03611981221147519

Abstract:
Aging of bitumen can lead to fatigue and non-load-associated cracking of asphalt pavements. Performance grade specifications include threshold limits for rheological properties from specific ranges of binder behavior after laboratory aging. Some specifications include aging ratios (ARs) to limit the rate at which properties deteriorate. This study compares the evolution of interrelationships and ARs of performance parameters in specific areas in Black Space to understand the relative susceptibility of the binder behavioral spectra to aging. Unmodified and polymer modified binders are aged with the rolling thin film oven and pressure aging vessel, and tested with the dynamic shear and bending beam rheometers. It is seen in the study that there are both related and unrelated aging trends in the distinct stiffness-related ranges. Correlations in parameter development significantly improve when binders are grouped by similar features such as modification type or origin. Binder source and modification type and degree greatly dictate aging trends in the high-stiffness range. In the low-stiffness range, the initial hardness of the binder is indicative of aging potential. The evolution of properties may be influenced by either modification or binder source in the intermediate domain. When considering ARs for specifications, combining complementary ARs may provide reciprocal insights into binder aging.
, , Prabesh Bhandari, Sahadat Hossain
Transportation Research Record: Journal of the Transportation Research Board; https://doi.org/10.1177/03611981221150413

Abstract:
Civil engineering infrastructures constructed on unsuitable foundation soil are prone to large deformation and bearing capacity failure. A common and traditional approach employed by the Texas Department of Transportation (TxDOT) is to remove in situ soil and replace it with suitable fill material. However, this method can be time-consuming and expensive. To minimize construction time and cost, the use of recycled plastic pins (RPPs) for ground improvement needs to be evaluated as an effective and sustainable technique. This study aims to evaluate the effectiveness of RPPs in improving unsuitable foundation soils. An extensive field-testing program was conducted on RPP-reinforced soil. In the field, four identical sections were constructed, of which three were reinforced with RPPs of different sizes and spacings, and the fourth was left unreinforced so that it could act as a control. Performance monitoring for all four test sections was conducted using inclinometer and pressure plates for more than 2 years. According to the field monitoring data, the reinforced section settlement was reduced by up to 84%, and RPPs carried 78% of the total load. Therefore, RPPs show promising potential for improving unsuitable foundation soil.
Shuyan Ma, Pei Zhang, , Ziwei Zhao
Transportation Research Record: Journal of the Transportation Research Board; https://doi.org/10.1177/03611981221147512

Abstract:
Both high-speed rail (HSR) and air transportation networks have important impacts on accessibility to cities. However, few attempts have been made to analyze the combined modal accessibility of HSR and air, especially in the case of China. To fill this gap, this study aims to measure accessibility under a combined HSR and air transportation network in China. Average travel time (ATT), weighted average travel time (WATT), and potential accessibility (PA) are employed as indicators of accessibility. The results show that inter-urban accessibility under the combined network shows a decreasing trend from the central to the surrounding region, with the level of combined network urban accessibility significantly higher than that of either individual network. Under the ATT, WATT, and PA indicators, the combined network outperforms the HSR network by 46.53%, 47.69%, and 49.23%, respectively, and the airline network by 15.49%, 13.17%, and 75.45%, respectively. In addition, the combined network shows a more equitable distribution of accessibility than that of the HSR network.
Ashley S. Carey, W. Griffin Sullivan, Leigh E.W. Ayers,
Transportation Research Record: Journal of the Transportation Research Board; https://doi.org/10.1177/03611981221150925

Abstract:
This paper documents the use of the 4 x 8 in. plastic mold (PM) device on two full-depth reclamation (FDR) field projects where cement-stabilized material containing large aggregates were used. PM device specimens were assessed to understand project variability as well as investigate potential in-field curing protocols for early-age roadway trafficability. Additionally, PM device specimens were compared with cores to quantify early-age mechanical properties and relationships. The density of PM device specimens and cores were, on average, within 2% of one another. In some cases, on-site curing protocols produced strengths that were not statistically different from cores. Ultimately, the PM device was successfully implemented and capable of producing reliable and repeatable results that captured project variability.
Transportation Research Record: Journal of the Transportation Research Board; https://doi.org/10.1177/03611981221149729

Abstract:
In recent years, there has been growing attention on the electrification of the public transit network. Battery electric buses (BEBs) are among the promising alternatives to replace diesel-powered buses. However, the possible driving range from a full charge has proved a matter of concern, as has the waiting times of BEBs returning to terminal stops after completing their journeys. This study aimed to design an efficient electric transit network considering waiting times at terminal stops and two configurations of charger to avoid BEBs running out of charge: a fast charger with energy storage (ES) technology and one without. A queuing-based mathematical model was proposed. To validate the proposed model, we tested it on two sizes of network: the Mumford0 (small) and the Mumford2 (large). By conducting a sensitivity analysis, certain model parameters, including the power of fast chargers, duration of service interval, BEB energy consumption, and maximum allowable waiting time were found to have substantial impacts on the electric public transit network. ES chargers were found to have the potential to save 15.35% of total costs. Other analyses confirmed that altering the capacity of fast- and ES chargers could affect the number of chargers required in the transit network and the total cost. Policies are suggested for transit agencies to plan to optimize their electric transit networks.
Yuning Wu,
Transportation Research Record: Journal of the Transportation Research Board; https://doi.org/10.1177/03611981221150923

Abstract:
Rail defects, especially transverse defects (TDs), can pose risks to safe and efficient railroad operations. Effective rail defect detection is critical for the prevention of broken rail-induced accidents and derailments. In this study, a deep autoencoder (DAE) rail defect detection framework is developed to process ultrasonic A-scan data collected by a roller search unit and to identify the presence of TDs in rail samples. An autoencoder is a semi-supervised learning algorithm that identifies observations in a dataset that significantly deviate from the remaining observations and can be used for rail defect detection. Ultrasonic A-scan signals collected from both pristine and damaged rail segments are analyzed, where the pristine dataset is used to train a DAE model. To improve the accuracy and sensitivity of defect detection, we optimize the architecture and hyperparameters of the DAE model. Moreover, we evaluate the performance of two features extracted from the DAE model through receiver operating characteristic curves and confusion matrix. The DAE features outperformed conventional knowledge-driven features in the accuracy and robustness of defect detection, especially with the presence of noise.
, Abolfazl Karimpour,
Transportation Research Record: Journal of the Transportation Research Board; https://doi.org/10.1177/03611981221151066

Abstract:
Queue length is one of the most important metrics required for the performance assessment of signalized intersections. However, the current methodology of estimating queue length in the literature suffers from several drawbacks, including unstable estimation and the requirement for multiple data sources. Moreover, for single-channel advance detection, which is a common detection configuration for signal control in many U.S. cities, manual parameter calibration is required. To bridge these gaps, this study proposes a cycle-based maximum queue length estimation method based on: (a) the empirical observation of breakpoints in the time gap between successive actuations; and (b) the identification of queue status for all detector actuations in a cycle. Maximum queue length for cycles with long queues is estimated based on the saturation flow rate and the trajectory of the last vehicle in the queue. The proposed methodology was implemented on two study intersections in Tucson, Arizona. Results showed that using the proposed method, queue length can be estimated with mean absolute percentage errors of 14.77% and 15.1% and mean absolute errors of 25 ft and 42.5 ft. The results showed significant improvement in queue length estimation from single-channel detection data when compared with similar methods in the literature. The proposed method can help transportation agencies accurately estimate queue length at intersections with single-channel advance detection without the need for manual field data collection and without installing lane-by-lane detection.
Moses Akentuna, Qiming Chen, Zhongjie Zhang
Transportation Research Record: Journal of the Transportation Research Board; https://doi.org/10.1177/03611981221150398

Abstract:
Hot mix asphalt (HMA) overlays are constructed on Portland cement concrete (PCC) pavements to improve long-term performance. A significant disadvantage of using HMA overlays on PCC pavements is the development of reflection cracks. Reflection cracks are influenced by traffic loads and periodic temperature changes. The objective of the study was to compare field performance of two slab-fracturing (i.e., break and seat, and rubblization) techniques commonly used in Louisiana, U.S. Four PCC pavement rehabilitation projects with at least one slab-fracturing technique and a corresponding control section were evaluated. Field structural capacity and performance data were collected and analyzed to determine the effect of each reflection-crack mitigation technique on performance. Resilient modulus (Mr) of the existing subgrade was found to significantly influence the structural and functional performance of the pavement sections evaluated. Pavement sections with weaker subgrades were shown to be not suitable for slab-fracturing rehabilitation techniques. For the four field projects evaluated, rubblized test sections showed higher cracking resistance than the control sections. The break and seat technique did not consistently improve or reduce the crack resistance of pavement sections compared with their corresponding control sections because of variations in subgrade Mr values. Sections with smaller sized (i.e., 6 in. break pattern and rubblized particles) fractured particles exhibited higher cracking resistance. Rubblized and selected break and seat sections for the field projects evaluated exhibited lower overall performance compared with their corresponding control sections, which is attributed to other underlying subsurface conditions. Additional study is required to continuously monitor the pavement sections.
Thiago Vinícius Louro, , Gabriel Torresin de Oliveira Gardin,
Transportation Research Record: Journal of the Transportation Research Board; https://doi.org/10.1177/03611981221150926

Abstract:
This research analyzed the factors influencing lateral distance and speed of motorized vehicles overtaking cyclists. The measurement apparatus consisted of an instrumented bicycle equipped with an ultrasonic sensor, a speed radar, GPS devices and a GoPro camera. The experiment was carried out along a predetermined route in the urban area of Londrina, in the state of Paraná, Brazil. A total of 36 tours were performed, wherein 2032 overtaking maneuvers were identified. Several factors were regressed on two dependent variables, namely the overtaking speed and the lateral distance, within a path analysis modeling framework to assess their contributions to the cyclist safety. The presence of painted bike lanes was shown to be the most important aspect, as lateral clearance increased by an average 31 cm compared with that for streets without this intervention. It should be noted though that this effect is higher for lanes with larger widths, with practically no influence on narrower lanes. Larger lateral distances were found in wider streets, whereas heavier vehicles and higher speed limits were associated with faster overtaking maneuvers. The most critical factor was related to cycling in commercial city zones where the combined effects posed a greater risk to cycling (i.e., higher overtaking speeds with shorter lateral distances). These findings shed light on relevant policies to promote cyclist safety and cycling attractiveness, such as expanding cycling infrastructure, decreasing street speed limits and informing citizens about the safest cycling routes in their urban environment.
Transportation Research Record: Journal of the Transportation Research Board; https://doi.org/10.1177/03611981221150245

Abstract:
Assigning inspection trains to monitor track quality is a standard procedure for maintaining railway system safety. The main challenges lie in lacking time and resources to perform the inspections because of the increasing traffic nowadays. To overcome these challenges, many consider adopting the on-board monitoring (OBM) technique for performing the inspections. This technique assigns commercial trains, instead of traditional track recording vehicles (TRVs), to monitor the track status, allowing railway operators to perform more inspections without affecting the traffic and using expensive inspection trains as well. However, compared with TRV data, the new OBM data are of lower data quality and have fewer features, although they can be recorded more frequently. Therefore, new methods should be developed for effectively applying the new data. This study develops four models, namely the linear regression model, Markov model, ordinary Kriging model, and Kalman filter model, for predicting the track status based on the OBM data. Data collected from the Switzerland railway network are used for verifying the models. Results show that the proposed models can effectively predict the degradation of the track status in different ways and, therefore, assist railway operators in scheduling maintenance tasks.
Back to Top Top