Understanding relationship between road median type and accident frequency

Road medians play an important role in the design of four or more lanes highways with high traffic volume and the large number of accidents. This study focused on effect of factors (such as traffic volume, road characteristics, land use and road median types) on the number of accidents. The data was collected from nationwide highway, and further used to build the models by using Generalized linear with Negative binomial model distribution classified by road median types including raised-, depressed-, flush-and barrier median. The result found that the increase in traffic volume and truck ratio are positively associated with more number of accidents in all four road median model. The finding also recommends that raised-, depressed-and flush median should be implemented within agriculture and rural area in order to decrease crashes frequency. The contributions of this study could be used as guideline regarding highways median type implementation decision-making to enhance road safety in Thailand

A Comparison of Contributing Factors between Young and Old Riders of Motorcycle Crash Severity on Local Roads

This study aims to identify the factors that influence the severity of motorcycle crashes on local roads, particularly given the high speeds often observed for motorcycles on these roads with low traffic volumes and numerous multi-leg intersections. Previous research has shown that a rider’s age can impact their speed behavior. To explore this issue, data on motorcycle crashes from 2015 to 2020 in Thailand—a middle-income developing country—were analyzed using a random parameter logit model with unobserved heterogeneity in means and variances, comparing young (<30-year-old) and older (>50-year-old) riders. The contributing factors were divided into four groups: driver, crash, environmental, and road factors. The transferability test yielded different results for the young rider and old rider models, indicating that it is appropriate to analyze these models separately. A constant value revealed that old riders were more likely to die in a crash than young riders. In terms of the random parameter, the local address and road surface variables were found to be significant in both models. The results of unobserved heterogeneity in means and variances identified significant variables in both models, including gender, exceeding the speed limit, lit roads, unlit roads, mobile phone use, and road surface. These findings were used to develop policy recommendations for reducing the severity of motorcycle crashes on local roads

Structural Equation Model of Factors Influencing the Selection of Industrial Waste Disposal Service in Cement Kilns

Industrial waste disposal in a cement kiln is an operation that includes waste disposal as well as the conversion of waste into renewable energy, which is a cement industry in many countries. This research studied business factors related to the intention to use co-processing industrial waste disposal service in cement kilns by surveying the data with questionnaires from 1251 customers nationwide. The objectives of this research were to study the relationship of business factors by using structural equation modeling to analyze factors influencing the selection of industrial waste disposal service in cement kilns. The study results found that customer attitude towards the following factors, including perceived ease of use, perceived usefulness, disposal price, service provider location, promotion, people, and a service provider’s infrastructure, influenced intention to use the service. The variables that customers gave importance to were the industrial waste disposal with zero wastes to landfill and the use of industrial waste relevant to the circular economy by using the industrial waste, which has a quality of renewable fuel in cement kiln as the renewable fuel of the cement furnace. According to the research results, service providers in cement kilns can potentially plan service strategies to achieve sustainability for further business operations in a highly competitive market

Evolution of Urban Haze in Greater Bangkok and Association with Local Meteorological and Synoptic Characteristics during Two Recent Haze Episodes

This present work investigates several local and synoptic meteorological aspects associated with two wintertime haze episodes in Greater Bangkok using observational data, covering synoptic patterns evolution, day-to-day and diurnal variation, dynamic stability, temperature inversion, and back-trajectories. The episodes include an elevated haze event of 16 days (14–29 January 2015) for the first episode and 8 days (19–26 December 2017) for the second episode, together with some days before and after the haze event. Daily PM2.5 was found to be 50 µg m−3 or higher over most of the days during both haze events. These haze events commonly have cold surges as the background synoptic feature to initiate or trigger haze evolution. A cold surge reached the study area before the start of each haze event, causing temperature and relative humidity to drop abruptly initially but then gradually increased as the cold surge weakened or dissipated. Wind speed was relatively high when the cold surge was active. Global radiation was generally modulated by cloud cover, which turns relatively high during each haze event because cold surge induces less cloud. Daytime dynamic stability was generally unstable along the course of each haze event, except being stable at the ending of the second haze event due to a tropical depression. In each haze event, low-level temperature inversion existed, with multiple layers seen in the beginning, effectively suppressing atmospheric dilution. Large-scale subsidence inversion aloft was also persistently present. In both episodes, PM2.5 showed stronger diurnality during the time of elevated haze, as compared to the pre- and post-haze periods. During the first episode, an apparent contrast of PM2.5 diurnality was seen between the first and second parts of the haze event with relatively low afternoon PM2.5 over its first part, but relatively high afternoon PM2.5 over its second part, possibly due to the role of secondary aerosols. PM2.5/PM10 ratio was relatively lower in the first episode because of more impact of biomass burning, which was in general agreement with back-trajectories and active fire hotspots. The second haze event, with little biomass burning in the region, was likely to be caused mainly by local anthropogenic emissions. These findings suggest a need for haze-related policymaking with an integrated approach that accounts for all important emission sectors for both particulate and gaseous precursors of secondary aerosols. Given that cold surges induce an abrupt change in local meteorology, the time window to apply control measures for haze is limited, emphasizing the need for readiness in mitigation responses and early public warning