Does the priority of ambulance guarantee no delay? a MIPSSTW model of emergency vehicle routing optimization considering complex traffic conditions for highway incidents.

Globally, traffic accidents on the highway network contribute significantly to a high fatality rate, drawing considerable attention from health institutions. The efficiency of transportation plays a vital role in mitigating the severe consequences of these incidents. This study delves into the issues of emergency vehicles experiencing delays despite having priority. Therefore, we construct mixed-integer linear programming with semi-soft time windows (MIPSSTW) model for optimizing emergency vehicle routing in highway incidents. We analyze the time-varying and complex traffic situations and respectively propose corresponding estimation approaches for the travel time of road segments, intersections on the urban road network, and ramp-weave sections on the highway network. Furthermore, we developed a modified cuckoo search(MCS) algorithm to solve this combinatorial problem. Optimization strategies of Lévy flight and dynamic inertial weight strategy are introduced to strengthen the exploration capability and the diversity of solution space of the CS algorithm. Computational experiments based on the Chinese emergency medical system data are designed to validate the efficacy and effectiveness of the MIPSSTW model and MCS algorithm. The results show that our works succeed in searching for high-quality solutions for emergency vehicle routing problems and enhance the efficacy of strategic decision-making processes in the realm of incident management and emergency response systems.

Analyzing Commute Mode Choice Using the LCNL Model in the Post-COVID-19 Era: Evidence from China.

The purpose of this paper is to gain an insight into commuting and travel mode choices in the post-COVID-19 era. The surveys are divided into two waves in Qingdao, China: the first-wave questionnaires were collected under the background of a three-month zero growth of cases; the second wave was implemented after the new confirmed cases of COVID-19. The latent class nested logit (LCNL) model is applied to capture heterogeneous characteristics among the various classes. The results indicate that age, income, household composition, and the frequency of use of travel modes are latent factors that impact users' attitudes toward mass transit and the private car nests when undergoing the shock of the COVID-19 pandemic. Individuals' trepidation regarding health risks began to fade, but this is still a vital consideration in terms of mode choice and the purchase of vehicles. Moreover, economic reinvigoration, the increase in car ownership, and an increase in the desire to purchase a car may result in great challenges for urban traffic networks.

Ultrasound Biomicroscopy Observation of Suspicious Primary Angle Closure Combined with the Relaxation of Zonule.

Purpose: To investigate the difference in anterior segment parameters between suspicious primary angle closure (PACS) patients and normal patients as assessed by ultrasound biomicroscopy (UBM). Methods: From June 2019 to November 2020, 39 patients (50 eyes) with PACS in the Ophthalmology Department of Qingdao University Affiliated Hospital who underwent phacoemulsification and intraocular lens implantation were selected as the PACS group. 32 patients (50 eyes) who underwent phacoemulsification and intraocular lens implantation were selected as the normal group. In addition to routine preoperative examinations such as visual acuity, noncontact intraocular pressure, axis length (AL), and ocular B-ultrasound examination, UBM examinations were also performed, including measuring the central anterior chamber depth (ACD), the maximum transverse diameter of the ciliary process at both ends (STS), the vertical distance between the anterior apex of the lens and the maximum transverse diameter at both ends of the ciliary processes (h), and angle opening distance (AOD500), iris-zonule distance (IZD), trabecular-ciliary process distance (TCPD), trabecular-iris angle (TIA), iris thickness (IT), trabecular-ciliary process angle (TCPA), and anterior placement of the ciliary body (APCB) at four quadrants (superior, nasal, inferior, and temporal quadrants). Results: Compared with the normal group, the PACS group showed statistically differences in AL, ACD, h, ACD/AL, h/STS, IZD, AOD500, TCPD, TIA, TCPA, and APCB (P < 0.05), and there were no significant differences in STS and IT between the two groups (P > 0.05). In the PACS group, there were significant differences in AL, ACD, h, ACD/AL, h/STS, IZD, TCPD, TCPA, and APCB between PACS patients with zonular relaxation and without zonular relaxation (P < 0.05), while there were no significant differences in STS, AOD500, TIA, and IT (P > 0.05). Conclusion: UBM quantitatively enables to identify the anterior segment morphology, especially the zonules in patients of suspicious primary angle closure combined with the relaxation of zonule. Accurate measurement of UBM can be used to predict whether patients with PACS are combined with zonular relaxation, so as to provide a clinical imaging evidence for the diagnosis.

Revealing spatiotemporal travel demand and community structure characteristics with taxi trip data: A case study of New York City.

Urban traffic demand distribution is dynamic in both space and time. A thorough analysis of individuals' travel patterns can effectively reflect the dynamics of a city. This study aims to develop an analytical framework to explore the spatiotemporal traffic demand and the characteristics of the community structure shaped by travel, which is analyzed empirically in New York City. It uses spatial statistics and graph-based approaches to quantify travel behaviors and generate previously unobtainable insights. Specifically, people primarily travel for commuting on weekdays and entertainment on weekends. On weekdays, people tend to arrive in the financial and commercial areas in the morning, and the functions of zones arrived in the evening are more diversified. While on weekends, people are more likely to arrive at parks and department stores during the daytime and theaters at night. These hotspots show positive spatial autocorrelation at a significance level of p = 0.001. In addition, the travel flow at different peak times form relatively stable community structures, we find interesting phenomena through the complex network theory: 1) Every community has a very small number of taxi zones (TZs) with a large number of passengers, and the weighted degree of TZs in the community follows power-law distribution; 2) As the importance of TZs increases, their interaction intensity within the community gradually increases, or increases and then decreases. In other words, the formation of a community is determined by the key TZs with numerous traffic demands, but these TZs may have limited connection with the community in which they are located. The proposed analytical framework and results provide practical insights for urban and transportation planning.

Exploring the impact of COVID-19 on individual's travel mode choice in China.

Travel activities and travel behaviors have been greatly affected by the outbreak of Covid-19. Facing the change of individuals' travel choices, policymakers have to make an appropriate response to mitigate negative consequences. This paper aims to explore how the COVID-19 would impact travel mode choice and the intention of car purchase. The data was collected from a large-scale survey conducted in June 2020 after the highest point. Random utility maximization (RUM), random regret minimization (RRM) and generalized regret minimization (GRRM) are employed to examine the effects of various factors on mode choice behaviors. The estimation results reveal that regret aversion psychology doesn't have a dominant proportion of decision choices, even if the congested condition of the mass mobility plays a significant role in the consideration of decision-making. Combined with the statistical results from the official departments, we concluded that public transport displays a great propensity on the long trip, and meanwhile, the industry of ride-hailing services has shocked sharply. In terms of the intention of traffic tool purchase, carless people prefer to buy electric two-wheel vehicles rather than automobiles. The research findings and the contribution to policy implications give assistance to authority in understanding citizens' travel mode preferences under the impact of COVID-19.

A multi-stage emergency supplies pre-allocation approach for freeway black spots: A Chinese case study.

This study presents a multi-stage random regret minimization (RRM) model as an emergency rescue decision support system to determine the emergency resource pre-allocation schedule for the freeway network. The proposed methodology consists of three steps: (1) improved accident frequency approach to identify the black spots on the freeway network, (2) stochastic programming (SP) model to determine the initial allocation plan sets, and (3) regret-based model in the logarithmical specification to select the most minimal regret one considering the factors of the response time, total cost and demand. The model is applied to the case study of 2014-2016 freeway network in Shandong, China. The results show that the random regret minimization (RRM) model can improve the full-compensation of SP model to a certain degree. RRM in logarithmical specification performs lightly better than random utility maximization (RUM) and RRM in the linear-additive specification in this case. This approach emerges as a valuable tool to help decision makers to allocate resources before traffic accident occurs, with the aim of minimizing the total regret of their decisions.