Department Of Transportation Research Articles

New hot-mix cold-laid mix design method with a superpave gyratory compactor

This study introduces a novel method for designing Hot-Mix Cold-Laid (HMCL) asphalt mixes, which are essential for pavement maintenance. In Texas, the current practice for HMCL mix designs adheres to the traditional Hveem method, employing a Texas Gyratory Compactor (TGC) in line with the Texas Department of Transportation (TxDOT) specifications. However, this research advocates for the use of a Superpave Gyratory Compactor (SGC), a more advanced and modern alternative. The SGC, widely used for Hot-Mix Asphalt (HMA) mix designs, provides more adjustable parameters and the ability to control compaction densities. Five types of industrial-based HMCL mixes were examined, each type having three levels of binder content. These fifteen laboratory-mixed HMCL mixes were used to mold SGC specimens at four compaction levels. This established the design gyration for SGC lab-molded densities within 94.0 ± 1.5 %. The investigation revealed that the existing specification might include mix designs with low compactability and weak correlations with field performance, due to their insensitivity to binder contents. The proposed method uses Cantabro mass loss test, IDEAL cracking test, and rutting test to characterize mix resistance to raveling, cracking, and rutting. The binder contents significantly affected these test results, leading to the exclusion of mixes with low compactability during testing. Thus, the new HMCL design method using an SGC enhances the current method.

Review of One Call Operator Membership and Exemptions for State Departments of Transportation

One Call centers are part of a nationwide system in the U.S. that aims to reduce the probability of excavators causing damage to underground utilities during construction projects. Laws dictating which utility operators must participate in One Call systems differ across states. In some states, certain utility operators have membership exemptions in One Call systems. However, these exemptions have come under scrutiny as they limit grant opportunities available for One Call centers. State Departments of Transportation (DOTs) are one group of institutions frequently exempted from One Call requirements, though they operate underground utilities as part of their transportation networks. To discern the impacts of exemptions or required membership in state One Call systems, this study involves a comprehensive literature review on One Call legislation, a national survey of state DOT subject-matter experts, and 12 in-depth case studies with DOT personnel. These efforts show that a definitive solution is not apparent. When a state DOT evaluates its One Call operator membership, the DOT must carefully consider many variables and potentially complex interactions. Moreover, quantifying the costs and benefits of operator membership proves challenging, as they vary as a result of the diverse criteria. This study reveals that deciding on One Call memberships or exemptions at a national level is not judicious. In fact, the findings emphasize that the state DOT is the most suitable entity to determine whether the One Call operator membership is warranted. Thus, their voices should be decisive when deliberating over their One Call operator memberships.

Logistic Simulations to Assess the Effect of Florida Department of Transportation’s Incentive and Disincentive Specifications on Long-Term Asphalt Pavement Performance

Logistic Simulations to Assess the Effect of Florida Department of Transportation’s Incentive and Disincentive Specifications on Long-Term Asphalt Pavement Performance

Causes and Trends of Motorcycle Accidents

Road safety has long been considered as one ofthe social responsibilities to the Malaysian Government. Inthe visibility of this responsibilities, multiple bodies concernon road safety has been formed within the governmentdepartments, private agencies, and voluntary organizations.The current study was carried out to understand the recenttrend and statistics of road motorcycles in Kajang,Malaysia. The statistics for road accidents and the relatedcasualties in Malaysia from 2005 to 2008 was obtained fromthe Bukit Aman Police Headquarters. The statistics ofregistered motor vehicles in Malaysia will be provided byRoad Transport Department of Malaysia. Data will beanalyzed using SPSS software. Descriptive and hypothesistesting techniques were used to obtain the results based onthe stated objectives of the study. From the crash statistics,it can be revealed that Kajang has a relatively higherincidence of casualties (dead, seriously injured and lightlyinjured). In addition, the results show that the young ridersof motorcycles among the age of 16 to 20 years from themajority of those who die in motorcycles accidents.Moreover, it is recognized that the considerable percentageof the motorcyclists and the pillion riders did not wearsafety helmets when they were traveling on the roadsnetwork. The Malaysian government has to organize manymotorcycle safety campaigns in the coming few years.

Full-scale experimental investigation of prestressed concrete bridge girders strengthened with aluminium channels

The bridge network in South Carolina encompasses more than 9,000 structures, many of which were originally constructed to accommodate H10 (89 kN) or H15 (134 kN) truck loads and thus require strengthening to carry current loading standard (HL-93). The South Carolina Department of Transportation (SCDOT) has recognized that prestressed concrete channel bridge girders, a specific type of bridge superstructure, often face challenges in achieving adequate load ratings, based on flexural strength. Hence, it is imperative to explore strengthening methods for these girders. Aluminium alloys possess desirable properties that make them attractive as external reinforcement materials. While previous studies have investigated the use of aluminium alloys on small-scale reinforced concrete members, there is a lack of investigation on their use on full-scale prestressed concrete bridge girders. To address this gap, this study investigates the feasibility of utilizing aluminium alloy channels as an external reinforcement material on full-scale prestressed concrete channel bridge girders. The main goal of this paper is to propose a strengthening method for prestressed concrete channel girders that is cost effective and easily implemented in the field to reduce the number of load-posted bridges in the state of South Carolina. Nine girders from recently decommissioned bridges in South Carolina were tested under flexural loading conditions to failure. The test program consisted of six unstrengthened girders, one strengthened with bonded aluminium channels (SE), one strengthened with bonded and bolted aluminium channels (SEB), and one strengthened with bolted aluminium channels (SB). Before testing, a visual inspection of the girders was conducted to identify any existing deterioration, and each girder was given a condition rating based on the Specifications for the National Bridge Inventory (SNBI). Theflexuralicate that externally anchored aluminium alloy channels with bolts was the most effective strengthening method in terms of practicality and increase in the flexural strength. Moreover, the results also revealed that the measured flexural strength of the girders varied based on the extent of the observed girder deterioration.

Leveraging computer vision for predicting collision risks: a cross-sectional analysis of 2019–2021 fatal collisions in the USA

ObjectiveThe USA has higher rates of fatal motor vehicle collisions than most high-income countries. Previous studies examining the role of the built environment were generally limited to small geographic areas...

A Novel Network Framework on Simultaneous Road Segmentation and Vehicle Detection for UAV Aerial Traffic Images.

Unmanned Aerial Vehicle (UAV) aerial sensors are an important means of collecting ground image data. Through the road segmentation and vehicle detection of drivable areas in UAV aerial images, they can be applied to monitoring roads, traffic flow detection, traffic management, etc. As well, they can be integrated with intelligent transportation systems to support the related work of transportation departments. Existing algorithms only realize a single task, while intelligent transportation requires the simultaneous processing of multiple tasks, which cannot meet complex practical needs. However, UAV aerial images have the characteristics of variable road scenes, a large number of small targets, and dense vehicles, which make it difficult to complete the tasks. In response to these issues, we propose to implement road segmentation and on-road vehicle detection tasks in the same framework for UAV aerial images, and we conduct experiments on a self-constructed dataset based on the DroneVehicle dataset. For road segmentation, we propose a new algorithm C-DeepLabV3+. The new algorithm introduces the coordinate attention (CA) module, which can obtain more accurate segmentation target location information and make the segmentation target edges more continuous. Also, the improved algorithm introduces the cascade feature fusion module to prevent the loss of detail information in road segmentation and to obtain better segmentation performance. For vehicle detection, we propose an improved algorithm S-YOLOv5 by adding a parameter-free lightweight attention module SimAM. Finally, the proposed road segmentation-vehicle detection framework is utilized to unite the C-DeepLabV3+ and S-YOLOv5 algorithms for the implementation of the serial tasks. The experimental results show that on the constructed ViDroneVehicle dataset, the C-DeepLabV3+ algorithm has an mPA value of 98.75% and an mIoU value of 97.53%, which can better segment the road area and solve the problem of occlusion. The mAP value of the S-YOLOv5 algorithm has an mAP value of 97.40%, which is more than YOLOv5's 96.95%, which effectively reduces the vehicle omission and false detection rates. By comparison, the results of both algorithms are superior to multiple state-of-the-art methods. The overall framework proposed in this paper has superior performance and is capable of realizing high-quality and high-precision road segmentation and vehicle detection from UAV aerial images.

Reconnaissance report on geotechnical damage caused by Tropical Cyclone Jasper in December 2023

This paper is focussed on the Department of Transport and Main Roads (TMR) initial geotechnical response to damages caused by Tropical Cyclone Jasper (TC Jasper) to road infrastructure and batter slopes along the state-controlled road network in TMR’s Far North Queensland (FNQ) District of Queensland, Australia. TC Jasper delivered extreme rainfalls over six days between 13 and 18 December 2023 in FNQ District. The highest accumulated total being 2,096mm in the area of Port Douglas and Mossman north of Cairns. Within areas of the TC Jasper path, rare to extremely rare rainfall occurrences resulted in severe flooding and geotechnical damage and closure of key state-controlled roads in FNQ. The roads closed included all four range crossings providing access to the Northern Tablelands. Communities were isolated, and tourism and regional transport severely impacted. This paper provides a report on the geotechnical damage caused by TC Jasper to seven key state-controlled roads in TMR’s FNQ District, and outcomes from the event reconnaissance approach used by TMR’s Engineering and Technology Geotechnical Section in collaboration with TMR FNQ District office and RoadTek teams to re-open most of the closed roads and secure significantly damaged road sections within four days of the cyclone passing. Ongoing recovery efforts are progressively re-opening remaining roads.

Exploring determinants of freeway service area usage in the context of sustainable and collaborated development for transport and tourism

Freeway service areas (FSA) provide a variety of services for road users, but these services in some cases do not guarantee the satisfaction of road users. Understanding the factors that affect the satisfaction of FSA is crucial for transportation and tourism-related departments. This paper uses a structural equation model (SEM) to examine the relationships between geographical location, routine function and satisfaction with FSA, in the context of six representative FSAs in Shaanxi province, China. The samples are divided into three clusters to investigate the sensitivity of tourists with different travel demands to the above relationship. In addition, the ordered logit model is used to verify the results of SEM and analyze the influencing factors of FSA satisfaction. Results indicate that increasing attraction levels of transport and tourism are considered to be the key determinants in improving the satisfaction with FSA, and policies and suggestions should meet tourists’ different demands. Undifferentiated policies, while useful to help improve satisfaction with FSA, may have a negative impact on some certain groups, such as those on an official business trip. This study provides theoretical and practical insights into how relevant departments and organizations with respect to transport and tourism formulate strategies for the construction and sustainable development of FSA.

Assessment of Service Quality on Public Satisfaction in Motor Vehicle Testing: A Study of the Transportation Department in Paser Regency

In an increasingly competitive era of public service, understanding the factors that influence public satisfaction is crucial for enhancing service quality. The primary objective of this study is to identify and analyze the impact of five service quality dimensions—tangibles, reliability, responsiveness, assurance, and empathy—on public satisfaction. This research also aims to provide recommendations for improving service quality at the Department of Transportation in Paser Regency. The study employs a quantitative approach using a survey method. Data were collected from 60 respondents who had used motor vehicle testing services within the last six months. Purposive sampling was employed to determine the sample, and data were gathered through questionnaires adapted from the SERVQUAL instrument. Data analysis was conducted using Structural Equation Modeling (SEM) to examine the relationships between variables. The findings indicate that of the five service quality dimensions tested, only assurance and empathy have a positive and significant impact on public satisfaction. Assurance was the most dominant factor, highlighting that the knowledge and competence of staff in providing safe and reliable services are crucial to the public. Empathy also plays a significant role, as attention and understanding of individual needs enhance satisfaction. Conversely, the dimensions of tangibles, reliability, and responsiveness did not show a significant impact on public satisfaction, suggesting that other factors might be more influential in this context. The managerial implications of these findings include the need for improvements in supporting facilities, regular training for staff, increased responsiveness, and the development of empathetic attitudes. With these measures, it is expected that service quality can be significantly improved, ultimately enhancing public satisfaction.

Взаимосвязь инновационных и классических методик профессиональной направленности обучения физике в техническом вузе

The introduction of two forms of conducting a laboratory workshop in physics for students for engineering and technology studies in the sphere of marine heat and power engineering, electrical equipment and automation means is considered to the process of studying at the Federal State Budget Educational Institution of Higher Education “Astrakhan State Technical University”. The possibility of developing students' working skills in natural conditions with industrial devices and an engineering approach taking into account the multifactorial conditions of the experiment as an independent work in the framework of the workshop of technical creativity Applied Physics organized at the Department of General Engineering Disciplines and Ground Transport is shown. The formation of the professional orientation of interdisciplinary connections of students of the specialty Thermal Power Engineering and Heat Engineering is illustrated by the example of the development of the laboratory work Determination of the specific heat capacity of metals. The advantages of virtual laboratory work and the possibility of their use on the educational portal of the “Astrakhan State Technical University”, built on the Moodle virtual learning environment, are examined. An example of creating a virtual laboratory work Studying the law of conservation of momentum is considered. It is theoretically proved that the introduction of these types of work into the educational process in physics contributes to the optimally effective formation of general professional competencies and the professional orientation of students' education. The importance of introducing these types of laboratory work into the educational process of physics at the university for the development of students' analytical abilities, creativity and innovation, which is a prerequisite for studying of modern engineers in demand in the labor market in a rapidly changing world, is shown.

Evaluating of 14H-Piles’ Load Capacity in Cohesionless Soils for Edward’s Project Using ?-Method and Finite Element Method

Abstract: This paper presents a comprehensive study on evaluating the load capacity of 14H-piles in cohesionless soils for Edward's infrastructure project[1]. The project, overseen by the Federal Highway Administration (FHWA) and the Colorado Department of Transportation (CDOT), focuses on bridge replacements in Edwards, Colorado, with an emphasis on foundation improvements using driven pile foundations[2]. The research utilizes Finite Element Analysis (FEA) and the β-method to assess the total bearing capacity of 14H-piles in sandy soil conditions[3]. Field exploration, including Standard Penetration Tests (SPT), is conducted to determine soil parameters, followed by calibration of soil strength parameters. The study involves modelling the piles using the Soil-Structure Interaction 3-D program (SSI3D) and comparing the total bearing capacity obtained from FEA with nominal capacities calculated by the β-method. Additionally, the paper discusses load resistance and factor design, as well as the importance of static load testing for validation[4]. The results highlight the efficacy of FEA in predicting pile behaviour and provide valuable insights for foundation design in similar geological settings.

The implementation of parking policy in Cirebon City Kejaksan Square

Kejaksan Square has become a tourist attraction in Cirebon City since it was renovated in April 2021. However, the implementation of parking policies there still faces obstacles such as lack of public awareness, lack of commitment of officers in socializing parking rules, and lack of adequate parking infrastructure. This study aims to evaluate the implementation of parking implementation policies in the Cirebon City Kejaksan Square. Qualitative and descriptive research methods are used, by collecting data through observations, interviews, and documentation. Edwards III's theory of policy implementation is used as a theoretical framework. The results showed that communication, resources, disposition and bureaucratic structure affect the implementation of parking policies. Despite the obstacles, the active role of the Department of Transportation and the availability of adequate resources provided support for the success of the policy. The ultimate goal is to improve the quality of public facilities and infrastructure services that are environmentally friendly.

Analysis of Historic Pavement and Bridge Conditions and Alternative Funding Levels for the Michigan Department of Transportation

Analysis of Historic Pavement and Bridge Conditions and Alternative Funding Levels for the Michigan Department of Transportation

Evaluation of the Operational and Safety Effects of a Variable Speed Limit System in Virginia

Variable speed limit (VSL) systems have been broadly deployed to address safety and mobility concerns both in the U.S. and internationally. In June 2022, the Virginia Department of Transportation activated a VSL system on I-95 northbound about halfway between Washington, D.C. and Richmond, Virginia. While many past VSL deployments have attempted to address urban congestion or mitigate safety issues arising from inclement weather, this deployment was intended to address traffic congestion created by through traffic during peak recreational periods by encouraging more uniform speed selection, dampening the effects of shockwaves, and providing advance warning of congestion. This paper discusses the characteristics of the deployed system, as well as its safety and operational effects, using approximately 1 year of post-deployment data. Results show that drivers did respond to the VSLs, and that mean speeds and speed distributions changed during transitional flow. Early safety results also showed reductions in crash severity, although this finding is based on limited data.

Effects of non-subsidized industrial policies on embedding position of power lithium-ion battery manufacturers in global value chain: Firm level evidence from China

Given the phase-out of subsidies, the Chinese government has issued a series of non-subsidized industrial policies to support the development of the power Lithium-ion Battery (PLiB) industry, recognized as pivotal for achieving carbon neutrality in the transportation department. However, existing literature provides limited evidence on the contribution of non-subsidized industrial policies, particularly to the PLiB industry. To bridge this gap, using data of 31 PLiB listed firms and 279 relevant non-subsidized industrial policies, this paper analyzes the effects of non-subsidized industrial policies on the global value chain (GVC) embedding position. The results reveal that non-subsidized industrial policies significantly raise the GVC embedding position of Chinese PLiB firms, and the positive effects are prone to increase over the research period. Further investigation shows that there is heterogeneity among PLiB firms, with the raising effects on the GVC embedding position being more significant in eastern and middle PLiB firms, private PLiB firms and midstream PLiB firms. The mechanism verification shows that non-subsidized industrial policies raise GVC embedding position of PLiB firms through technological innovation effect and scale economy effect, while competitiveness effect does not give full play. These findings provide important recommendations for better design of the industrial policies to improve the international competitiveness of PLiB industry and other strategic emerging industries.

Resource Allocation in an Uncertain Environment: Application to Snowplowing Operations in Utah

We consider a two-stage planning problem where a fleet of snowplow trucks is divided among a set of independent regions, each of which then designs routes for efficient snow removal. The central authority wishes to allocate trucks to improve service quality across the regions. Stochasticity is introduced by uncertain weather conditions and unforeseen failures of snowplow trucks. We study two versions of this problem. The first aims to minimize the maximum turnaround time (across all regions) that can be sustained with a user-specified probability. The second seeks to minimize the total expected workload that has not been completed within a user-specified time frame. We develop algorithms that solve these problems effectively and demonstrate their practical value through a case application to snowplowing operations in Utah, obtaining solutions that significantly outperform the allocation currently used in practice. Funding: Financial support from the Utah Department of Transportation [Grant 218138]; the National Science Foundation [Grant CMMI-2112758]; and the Mountain-Plains Consortium [Grant 637] is gratefully acknowledged. Supplemental Material: The e-companion is available at https://doi.org/10.1287/trsc.2023.0024 .

Resiliency Against Flooding in Pavement Geotechnics: Practice Review of State Transportation Agencies

Extreme weather events driven by climate change pose significant threats to our transportation infrastructure, particularly road pavements, in the United States. This paper proposes a guiding framework for designing resilient pavements. The framework was established after comprehensive reviews of the state of practice from pavement design manuals and construction-, implementation-, and practice documents publicly available on websites of state departments of transportation (DOTs) across the country. The objective of this study was to evaluate the infrastructure flood readiness and awareness of transportation agencies based on the state DOT website surveys. Qualitative analyses of transportation agency engineering and construction manuals revealed a varying degree of consideration among the different states for resiliency in transportation infrastructure design policies. Web scraping of state DOT websites highlighted the awareness levels of resiliency and sustainability issues concerning pavements. The importance of constructing permeable pavement base layers to alleviate flood-induced damage was investigated for assessing moisture infiltration effects on pavement performance and how to incorporate these improvements into mechanistic-empirical pavement design concepts. The findings underscored the need to incorporate climate change stressors and predictive climate data modeling in pavement design to enhance infrastructure resilience. Through study findings and considering implementation of the guidelines proposed in this paper, transportation engineers and state agencies are anticipated to be able to better prepare for future extreme weather challenges and safeguard the nation’s transportation assets.

Ensemble Machine Learning Classification Models for Predicting Pavement Condition

Forecasting pavement performance condition is essential within the pavement management system to optimize decisions with regard to planning maintenance and rehabilitation projects. Accurate forecasts facilitate timely interventions and assist in formulating cost-effective asset management plans. Data-driven machine learning models that utilize historical data to improve forecasting precision have gained attention in the field of asset management. Although numerous studies have employed regression-based models to forecast pavement condition, transportation asset management often operates according to condition index ranges rather than exact values. Therefore, classification models are suitable for predicting pavement condition grades and determining the appropriate maintenance type for pavement assets. This research focuses on developing five machine learning classification models to predict pavement condition: random forest; gradient boost; support vector machine; k-nearest neighbors; and artificial neural network. To enhance prediction performance, these models are integrated using ensemble methods, including voting and stacking. The classification models are developed using a dataset from the Georgia Department of Transportation that documented the condition of asphalt pavements for predefined maintenance sections between 2017 and 2021. A voting ensemble model constructed with the two best-performing individual classification models reached the highest accuracy rate at 83%. Although the performance of individual models fluctuates, ensemble models consistently produce a top-tier performance regardless of the variations in data sampling. Therefore, ensemble methods are recommended for developing pavement condition prediction models to improve accuracy and achieve a more consistent quality of predictions. The findings of this research will provide transportation agencies with information to help them strengthen their forecasting practices in relation to pavement condition, thereby improving their maintenance planning and cost savings.

MASH TL-3 Evaluation of the Hawaii Department of Transportation 34 in. Tall Aesthetic Bridge Rail with Pedestrian Rail and Sidewalk Options

Recommended guidelines were provided for the shape and size of aesthetic features added to roadside barriers in National Cooperative Highway Research Program Report No. 554, but limited full-scale crash testing has been performed on barriers with aesthetic features, especially in combination with sidewalks and pedestrian railings, each of which may contribute to increased propensity for vehicle snag, vehicle instabilities, and occupant risk metrics. A Hawaii Department of Transportation (HDOT) bridge rail design with vertical faces and aesthetic recessed panels was evaluated to Manual for Assessing Safety Hardware (MASH) TL-3 impact conditions in three configurations: stand-alone; in combination with a pedestrian handrail installed on the back side of the barrier system; and in combination with a pedestrian rail and 6 ft long x 6 in. tall sidewalk. The 34 in. tall aesthetic concrete bridge rail consisted of segments measuring 11 ft long at upstream and downstream ends and three 22 ft long, consecutive interior segments. MASH test designation Nos. 3-10 and 3-11 were performed on the stand-alone system and with the sidewalk and pedestrian rail, and test designation 3-11 was performed on the system on level terrain with handrail. Results indicated that the HDOT 34 in. tall aesthetic concrete bridge rail was crashworthy in all of the configurations evaluated.