Local Road Agencies Research Articles

Enhancing local road pavement condition prediction using Bayesian-optimized ensemble machine learning and adaptive synthetic sampling technique

ABSTRACT Pavement condition prediction helps road agencies to schedule maintenance, rehabilitation, and reconstruction, and to allocate limited funds and resources to such activities. Compared to state highways, pavement performance prediction for local roads has received relatively little attention in the literature due to perceptions of low importance, low levels of investment in data collection, poor data quality, and high variation within the data elements. Additionally, local road pavement condition data may suffer from dataset imbalance, often leading to unreliable condition predictions. Hence, this paper introduces a methodology to predict local pavement condition using various single estimator and ensemble machine learning (ML) models along with the adaptive synthetic sampling method. The study develops nine (9) Bayesian-optimised ML models: category boosting (CatBoost), adaptive boosting, decision tree, extra trees, gradient boosting, light gradient-boosting machine, k-nearest neighbour, random forest, and artificial neural network. The ensemble ML and CatBoost were found to exhibit the best model performance, with an average testing accuracy of 0.82, specificity of 0.81, sensitivity of 0.63, and F-measure of 0.61. These results underscore the efficacy of ensemble ML models in pavement condition prediction. The proposed approach can be beneficial to local road agencies in their long-term planning, scheduling, and budgeting.

Kalman filter updating of rutting predictive models in flexible pavements using measured field data

ABSTRACT Predicting pavement rutting is associated with significant uncertainties that often lead to inefficient maintenance planning. The predictive performance of rutting models is exacerbated in local road agencies and developing countries that rely on generic and knowledge-based models which are typically unreliable if used without adaptation, validation, or calibration. This study aims at developing a probabilistic framework that employs Ensemble Kalman Filter (EnKF) techniques to update the parameters associated with generic rutting predictive models while accounting for the prevailing uncertainties. When coupled with a continuous influx of measured data, the EnKF framework sequentially updates the generic models and minimizes prediction errors in real-time. The robustness of the presented scheme is demonstrated through a numerical example, and its sensitivity to the use of different generic curves as starting points is examined. The results indicate that the EnKF framework improves the accuracy of rutting predictions by up to 60% and that accuracy remains within tolerable limits whilst varying the range of the uncertainty in the measurements or the initial states. The paper concludes with a discussion of how practitioners can integrate the outcomes of the presented framework to enact maintenance policies that minimize the financial cost at the project and network levels.

Developing Transportation Livability-Related Indicators for Green Urban Road Rating System in Taiwan

Although indicators in rating systems have been initiated to measure and promote the sustainability performance of roadway projects in some developed countries, applying those indicators to other regions/countries may still be difficult. In response to the United Nations’ sustainable development goals, local road agencies in Taiwan urgently need to establish systematic and quantifiable sustainable roadway strategies. As part of the project to develop a green urban road rating system in Taiwan, this study aims to develop transportation livability-related indicators (TLIs) and identify critical barriers to TLI application in Taiwan’s urban road system. To this end, the research employed an adaptive approach that integrates top-down and bottom-up approaches. The top-down approach included the comprehensive literature review and panel discussion to derive four TLIs and 21 corresponding requirements, and nine potential barriers to hold the indicator adoption. Four TLIs are pedestrian facilities, universal design, multimodal transportation, and utility facilities. The bottom-up approach used the Analytic Hierarchy Process (AHP) to assign weights to proposed indicators/requirements. Four critical barriers were also investigated through the Weighted Sum Model (WSM) method, namely unfavorable in-situ conditions, lack of stakeholders’ coordination, unsupported government policy and regulation, and limited budget and schedule. The findings can be beneficial to engineers and decisionmakers to enhance the livability standard of urban streets. The framework proposed in this research can be applied to other roadway characteristics aspects in different regions/countries.

Applicability of smartphone-based roughness data for rural road pavement condition evaluation

ABSTRACT Rural roads play a pivotal role in facilitating connectivity for the rural communities by providing access for their economic and social needs. Due to lack of funding and other resources, maintenance decision making is often done in an ad-hoc and subjective manner. Moreover, the inability to collect extensive data as needed to run most pavement management systems and technical expertise required has resulted in the low usage of such systems by local road agencies. Therefore, there is a need to develop a cost-effective, simplified approach for network-level pavement condition evaluation to assist in pavement maintenance management. The study explores the applicability of smartphone-based roughness data to assess the pavement condition of rural roads, and it is compared with the results from a Class III type roughness measurement equipment. Result show it has good correlation, which suggests it has sufficient accuracy when compared to the conventional roughness measurement methods. Furthermore, it is established that roughness results accurately represent the presence of pavement distresses and the overall pavement condition in the rural roads that are considered in maintenance decision making. The findings from the study would provide a cost-effective pavement condition data collection method that can be adopted for network-level condition evaluation in low volume roads.

Development and Application of a Sustainable Management System for Unpaved Rural Road Networks

For the sustainable management of rural roads, social, institutional, technical, economic and environmental aspects should be considered under a long-term perspective. The current practice in developing countries is that only some of these key sustainable aspects are considered in the management process. In addition, rural roads maintenance management is commonly performed under a short-term basis, not considering the life-cycle costs and benefits in the economic analysis and project prioritization. This paper presents the development of a sustainable management system for rural road networks and its application in developing countries. The approach considers the development of a sustainable framework, application of a network-level condition evaluation methodology, condition performance models for gravel and earth roads, cost-effective maintenance standards, a long-term prioritization procedure that accounts for sustainable aspects, and a computer tool that integrates the system components. The management system has been applied and validated in two unpaved rural road networks in developing countries, located in Chile and Paraguay. Sensitivity analysis was carried out to assess the impacts of input parameters in the performance of developed system. As a result of the research an adaptable and adoptable sustainable management system for rural networks has been developed to assist local road agencies in developing countries.

Pavement Management System for local administrations: Guidelines in the Republic of San Marino

The Republic of San Marino, located in mid-Italy and looking the Adriatic Sea from the Monte Titano, is one of the smallest and oldest republics in the world. Since 2016, the University of the Republic of San Marino (UniRSM), the national road agency (Azienda Autonoma di Stato per i Lavori Pubblici, AASLP) and the government authority (Segreteria di Stato per il Territorio e l’Ambiente, SST) have been working together for using a tailored pavement management system (PMS). The planning pillar is the rational use of national financial resources through the coordination with other public institutions, such as the Geographic Information System office (Sistema Informativo di Territorio, SIT) and the agency for public services (Azienda Autonoma di Stato per i Servizi pubblici, AASS), a continuous monitoring of the road network serviceability, tight relationships with construction enterprises and mix-plants operating in the territory and the implementation of eco-sustainable maintenance procedures. As small state or local road agencies substantially differ from highway or airfield administrations in terms of resources, policy and potentialities, they need their own standards and procedures. This paper describes the maintenance strategy adopted in the Republic of San Marino, aiming to highlight and to suggest items of paramount importance for small states and local road agencies.

Improving Role of Construction Industry for More Effective Post-Disaster Emergency Response To Road Infrastructure in Indonesia

Geo- and hydro-meteorological disasters typically caused disruptive impact to road networks due to damaged road infrastructure, which in turn disconnect access to and isolate the disaster affected areas. Road clearing work and emergency road recovery operation are considered a priority to reconnect the access during post-disaster emergency response. However, the operation is not always smooth and in many cases delayed due to various problems. An investigation is conducted to understand the current practice of post-disaster emergency road recovery operation in Indonesia and to study possible participation of construction industry in order to improve its effectiveness. In-depth interviews with Local Disaster Management Agencies (BPBDs) and local road agencies in West Java Province were conducted to understand current practices in emergency road recovery operation and to view perspectives on local contractor participation. The surveys showed supports from the local governments for contractor involvement as long as it is still under guidance of related agencies (Ministry of Public Works and Housing) despite some possible obstacles from the current regulation that may hamper contractors’ participation, which indicate that there is a potential role of construction industry for more effective post-disaster emergency response, provided that contractor associations are involved and existing procurement regulation is improved.

REDUCING ROAD SALT APPLICATION BY CONSIDERING WINTER MAINTENANCE NEEDS IN PARKING LOT DESIGN

INTRODUCTION Winter snow and ice can have a significant impact on our mobility, whether on foot or by car. Alongside plowing, arguably the greatest tool in combating snow and ice is salt. The most commonly used salt for winter maintenance is Sodium Chloride (NaCl), the same salt used in food and water softeners, is applied to roads, sidewalks, and parking lots as it is an effective deicer when temperatures are between 0°C and −12°C. Studies have shown that deicing with salt reduces accidents by 88% and injuries by 85% (Salt Institute 2017). The effectiveness of road salt, as well as its relative affordability, means that as much as four million tonnes may be applied annually in Canada for deicing (Environment Canada 2012). However, while salt is relatively inexpensive to purchase, there are a number of external costs that are becoming increasingly apparent. These include corrosion of vehicles and infrastructure like concrete, bridges, and water mains; damage and staining to the interior and exterior of bu...

Evaluation of the Use of Magnesium Chloride for Surface Stabilization and Dust Control on Unpaved Roads

Gravel roads are an important portion of the road network in western Argentina, and their maintenance requires a huge amount of economic and human resources. Recently, the use of alternative treatments based on the application of mineral salts such as hydrous magnesium chloride, also known as bischofite, has been introduced in this region. Such treatments are being applied for dust control and surface stabilization on unpaved roads. This paper presents the main results obtained during a research project carried out by the National University of San Juan, Argentina, along with local road agencies and companies. Test sections of gravel roads were treated with bischofite applied in two ways. Over 18 months, measurements of surface roughness and dust emission were made on those sections. The main results show that the use of bischofite contributed to a notable reduction in the evolution of roughness and dust emission as compared with untreated gravel sections. Bischofite appears to be appropriate not only for the environment but also for road agencies and road users; important cost savings were verified through economic assessments that compared treated and untreated gravel road sections.

Calibration of Distress Models from the Mechanistic–Empirical Pavement Design Guide for Rigid Pavement Design in Argentina

This paper presents the main results of a calibration of distress models from the Mechanistic–Empirical Pavement Design Guide (MEPDG) to local conditions in Argentina to be used in rigid pavement structural design. Test sections with rigid pavements were selected to cover a wide range of climatic conditions in the central region of the country. Local road agencies provided information about pavement structure, traffic volume, and load spectra. Field distress data and international roughness index (IRI) values were collected and processed with MEPDG software; calibration factors were determined for the different distress models of rigid pavements. The accuracy of distress prediction was significantly improved if calibration factors that considered additional influence of climatic conditions, soil and base type, slab length, and pavement age were incorporated into the transverse joint-faulting and transverse-cracking models. Through the use of calibrated factors instead of default values provided in MEPDG models, the errors in distress predictions were reduced by more than one-half in all cases. Construction procedures seemed to influence the IRI roughness prediction. Better calibration results were obtained if different after-construction IRI values were considered for pavements constructed before and after the 1990s to reflect the difference between older and newer constructive techniques.

Development of Surfacing Criteria for Low-Volume Roads in South Dakota

On a daily basis, local road agencies in South Dakota face the challenge of how to maintain low-volume roads cost-effectively. Specifically, agencies are faced with the decision of determining when it is most economical to maintain, upgrade, or downgrade a road's existing surface. To assist decision makers with maintenance and rehabilitation decisions, the South Dakota Department of Transportation (SDDOT) initiated a study in 2002 to investigate surfacing criteria for low-volume roads. The overall objective of this research is to create a process that allows users to compare the costs associated with different types of roads to provide assistance in deciding which surface type (hot-mix asphalt, blotter, gravel, or stabilized gravel) is most economical under a specific set of circumstances. In addition to incorporating economic factors into the analysis, the process allows the user to consider other noneconomic factors that are more subjective and difficult to quantify. The process used during this study is flexible enough to allow users to consider any combination of agency costs incurred by the agency for maintaining its roads, user cost factors such as vehicle operating costs or crash potential, and noneconomic factors such as politics and housing densities. The methodology was created with agency cost and user cost models developed on the basis of specific road section information supplied by various local agencies in South Dakota, average daily traffic and crash occurrence information supplied by the SDDOT, information obtained through a literature search, and input from members of the project's technical panel.

Part 3: Low-Volume Roads: Pavement Management and Climatic and Seasonal Effects: Development of Surfacing Criteria for Low-Volume Roads in South Dakota

On a daily basis, local road agencies in South Dakota face the challenge of how to maintain low-volume roads cost-effectively. Specifically, agencies are faced with the decision of determining when it is most economical to maintain, upgrade, or downgrade a road's existing surface. To assist decision makers with maintenance and rehabilitation decisions, the South Dakota Department of Transportation (SDDOT) initiated a study in 2002 to investigate surfacing criteria for low-volume roads. The overall objective of this research is to create a process that allows users to compare the costs associated with different types of roads to provide assistance in deciding which surface type (hot-mix asphalt, blotter, gravel, or stabilized gravel) is most economical under a specific set of circumstances. In addition to incorporating economic factors into the analysis, the process allows the user to consider other noneconomic factors that are more subjective and difficult to quantify. The process used during this study is flexible enough to allow users to consider any combination of agency costs incurred by the agency for maintaining its roads, user cost factors such as vehicle operating costs or crash potential, and noneconomic factors such as politics and housing densities. The methodology was created with agency cost and user cost models developed on the basis of specific road section information supplied by various local agencies in South Dakota, average daily traffic and crash occurrence information supplied by the SDDOT, information obtained through a literature search, and input from members of the project's technical panel.

Challenges and Strategies for Local Road Safety Training and Technology Transfer

A significant increase in the safety of transportation networks in the United States and throughout the world will require the direct involvement of local jurisdictions (e.g., counties, townships, villages, and cities). In 1998, approximately 4 out of 10 fatalities in the United States occurred on collector and local roadways. Local road agencies need to have the skills to identify, evaluate, and mitigate safety concerns. Effective local road safety training, technology transfer, and resources are essential. A number of challenges need to be met to complete these tasks, but current local road safety training and technology transfer programs and strategies also offer opportunities. Some of these challenges are identified and discussed, and several current and potential programs and strategies for local road safety training and technology transfer are described. Relevant results from a recent FHWA and AASHTO international scan tour on the management and organization of comprehensive highway safety programs are also presented and used to support the suggestions provided. A synopsis of the relevant discussions from a recent workshop on highway safety workforce development, sponsored by FHWA, AASHTO, TRB, and ITE, is also offered. The objective is to initiate discussion about the need for and development of a comprehensive and cost-effective local safety training and technology transfer program.

Starting a Safety Improvement Program for Rural Unpaved Roads

A prototype safety improvement program (SIP) developed specifically for unpaved roads is presented. The combination of high mileage, low traffic volume, and limited budgets makes it difficult for local agencies to adopt traditional SIPs. The presented SIP for unpaved roads is economically and procedurally appropriate for local road agencies. It provides a systematic means of prioritizing road sections for safety analysis and identifying safety improvement needs. One of the many unique features of the program is its “partnering” approach of involving public road users in the safety improvement process. Results of case studies that validate the procedure are included.