The safety of work zones is a critical issue for drivers, transportation agencies, and governing authorities. In particular, the vehicles that perform lane changes in the proximity of the work zones involving lane closure, pose a significant threat to the safety of the public and the work zone workers, as they need to complete a forced merging. Yet, there is no comprehensive simulation framework to examine the work zone traffic safety under different compliance distributions of the drivers to the warning delivery for the work zone in a mix-autonomy operation of autonomous and human-driven vehicles. To fill this void, we present an integrated microsimulation framework to assess the correlation between the number of vehicles that perform late merge at the taper (LMT) and traffic mobility and safety under different empirical compliance distributions of the drivers to the warning delivery for the downstream work zone.
We employ different work zone configurations to illustrate the relationship between late merges at the taper and performance indicators for traffic mobility and safety of the work zone under a variety of work zone configurations. Simulation results show that compliance distribution significantly impacts the number of late merges at the taper (LMTs) and thereby traffic safety and efficiency. Our findings demonstrate that when human-driven vehicles exhibit high compliance behavior to the merging warning signs, it can offset the impact of the lower percentage of market penetration rate (MPR) levels for autonomous operation to achieve comparable traffic safety and efficiency. We further employ the conflation of microsimulation observations and data-driven models to design a regression model to predict LMTs as an indicator for traffic conditions using the work zone configuration as input variables. In particular, we address the heterogeneity induced by the compliance distribution of drivers by sampling the data points from the distribution to capture the diversity in compliance behaviors of the drivers. Our findings can provide insights for practitioners and researchers regarding the optimal compliance distribution using the performance measurements demonstrated in this work.
As communication and trust are both linked with safety, this paper aims to investigate their contribution to aviation maintenance incidents and accidents. For this purpose, the content analysis method is used to investigate whether trust and communication factors were present in aviation maintenance occurrences. Content analysis is used as a qualitative and quantitative tool. For the data analysis, apart from direct investigation for keywords throughout the material for analysis (aviation accident/incident reports with maintenance involvement), a survey tool was also employed. The items of this survey tool (Communication and Trust Question Set) were used to filter the reports’ text to indirectly identify the two factors under examination (communication and trust). As a qualitative tool, the content analysis yielded results via mapping and narrative techniques. As a quantitative tool, results were obtained and reported with the help of descriptive statistics (counts, frequencies). The results indicated that elements of trust and communication are indirectly detectable in aviation maintenance occurrences. Both ineffective communication and lack of trust were identified as a key accident/incident causal condition. Interpersonal trust is recommended to be included in the implementation requirements of any communication system. The limitations associated with the difference in the structure and consistency of the examined material are also discussed.
Efficiency of first and last mile transportation is a vital task that significantly contributes competitiveness of entire supply chain. Conducting systematic literature review is a first step in identifying imperfections and areas in need of further investigation. There is need to perform a comprehensive review of first and last mile activities, also including sustainability and green logistics aspects, as well as integration of autonomous robots into first and last-mile logistics for enhancing delivery efficiency and reducing operational costs, since these topics are becoming crucial. The aim of this study is to identify contemporary thematic groups related to first and last mile logistics and identify major gaps that require further investigation. In result, a research design was developed with specific selection of literature list, based on correlation analysis. Mapping of literature metrics was conducted with the purpose to identify research gaps and emerging trends. Eventually, major thematic groups of literature were created, and interconnections between them were investigated, allowing to discover multi-disciplinarity of first and last mile logistics studies.