Pilot Safety Research Articles

Malaria transmission-blocking vaccines Pfs230D1-EPA and Pfs25-EPA in Alhydrogel in healthy Malian adults; a phase 1, randomised, controlled trial

Malaria transmission-blocking vaccines target mosquito-stage parasites and will support elimination programmes. Gamete vaccine Pfs230D1-EPA/Alhydrogel induced superior activity to zygote vaccine Pfs25-EPA/Alhydrogel in malaria-naive US adults. Here, we compared these vaccines in malaria-experienced Malians. We did a pilot safety study then double-blind, block-randomised, comparator-controlled main-phase trial in malaria-intense Bancoumana, Mali. 18-50-year-old healthy non-pregnant, non-breastfeeding consenting adult residents were randomly assigned (1:1:1:1) to receive four doses at months 0, 1, 4·5, and 16·5 of either 47 μg Pfs25, 40 μg Pfs230D1 or comparator (Twinrix or Menactra)-all co-administered with normal saline for blinding-or 47 μg Pfs25 plus 40 μg Pfs230D1 co-administered. We documented safety and tolerability (primary endpoint in the as-treated populations) and immunogenicity (secondary endpoint in the as-treated populations: ELISA, standard-membrane-feeding assay, and mosquito direct skin feed assay). This trial is registered at ClinicalTrials.gov, NCT02334462. Between March 19, and June 2, 2015, we screened 471 individuals. Of 225 enrolled for the pilot and main cohorts, we randomly assigned 25 participants to pilot safety cohort groups of five (20%) to receive a two-dose series of Pfs25-EPA/Alhydrogel (16 μg), Pfs230D1-EPA/Alhydrogel (15 μg) or comparator, followed by Pfs25-EPA/Alhydrogel (16 μg) plus Pfs230D1-EPA/Alhydrogel (15 μg) or comparator plus saline. For the main cohort, we enrolled 200 participants between May 11 and June 2, 2015, to receive a four-dose series of 47 μg Pfs25-EPA/Alhydrogel plus saline (n=50 [25%]; Pfs25), 40 μg Pfs230D1-EPA/Alhydrogel plus saline (n=49 [25%]; Pfs230D1), 47 μg Pfs25-EPA/Alhydrogel plus 40 μg Pfs230D1-EPA/Alhydrogel (n=50 [25%]; Pfs25 plus Pfs230D1), or comparator (Twinrix or Menactra) plus saline (n=51 [25%]). Vaccinations were well tolerated in the pilot safety and main phases. Most vaccinees became seropositive after two Pfs230D1 or three Pfs25 doses; peak titres increased with each dose thereafter (Pfs230D1 geometric mean: 77·8 [95% CI 56·9-106·3], 146·4 [108·3-198·0], and 410·2 [301·6-558·0]; Pfs25 geometric mean 177·7 [130·3-242·4] and 315·7 [209·9-474·6]). Functional activity (mean peak transmission-reducing activity) appeared for Pfs230D1 (74·5% [66·6-82·5]) and Pfs25 plus Pfs230D1 (68·6% [57·3-79·8]), after the third dose and after the fourth dose (88·9% [81·7-96·2] for Pfs230D1 and 85·0% [78·4-91·5] Pfs25 plus Pfs230D1) but not for Pfs25 (58·2% [49·1-67·3] after the third dose and 58·2% [48·5-67·9] after the fourth dose). Pfs230D1 transmission-reducing activity (73·7% [64·1-83·3]) persisted 10 weeks after the fourth dose. Transmission-reducing activity of 80% was estimated at 1659 ELISA units for Pfs25, 218 for Pfs230D1, and 223 for Pfs230D1 plus Pfs25. After 3850 direct skin feed assays, 35 participants (12 Pfs25, eight Pfs230D1, five Pfs25 plus Pfs230D1, and ten comparator) had transmitted parasites at least once. The proportion of positive assays in vaccine groups (Pfs25 33 [3%] of 982 [-0·013 to 0·014], Pfs230D1 22 [2%] of 954 [-0·005 to 0·027], and combination 11 [1%] of 940 [-0·024 to 0·002]) did not differ from that of the comparator (22 [2%] of 974), nor did Pfs230D1 and combination groups differ (-0·024 to 0·001). Pfs230D1 but not Pfs25 vaccine induces durable serum functional activity in Malian adults. Direct skin feed assays detect parasite transmission to mosquitoes but increased event rates are needed to assess vaccine effectiveness. Intramural Research Program of the National Institute of Allergy and Infectious Diseases and US National Institutes of Health.

Risk of occurrence of electromagnetic interference from the application of transcutaneous electrical nerve stimulation on the sensing function of implantable defibrillators.

Transcutaneous electrical nerve stimulation (TENS) is an established method for pain relief. But electrical TENS currents are also a source of electromagnetic interference (EMI). Thus, TENS is considered to be contraindicated in implantable cardioverter-defibrillator (ICD) patients. However, data might be outdated due to considerable advances in ICD and cardiac resynchronization therapy (CRT) filtering and noise protection algorithm technologies. The aim of this pilot safety study was to re-evaluate the safety of TENS in patients with modern ICDs. One hundred and seven patients equipped with 55 different models of ICD/CRT with defibrillators from 4 manufacturers underwent a standardized test protocol including TENS at the cervical spine and the thorax, at 2 stimulation modes-high-frequency TENS (80 Hz) and burst-mode TENS (2 Hz). Potential interference monitoring included continuous documentation of ECG Lead II, intracardiac electrograms and the marker channel. Electromagnetic interference was detected in 17 of 107 patients (15.9%). Most frequent were: interpretations as a premature ventricular beats (VS/S) in 15 patients (14%), noise reversion in 5 (4.6%) which resulted in temporary asynchronous pacing in 3 (2.8%), interpretation as ventricular tachycardia/ventricular fibrillation in 2 (1.9%), and premature atrial beat in 2 (1.9%) patients. Electromagnetic interference occurrence was influenced by position (chest, P < 0.01), higher current intensity (P < 0.01), and manufacturer (P = 0.012). Overall, only intermittent and minor EMI were detected. Prior to the use of TENS in patients with ICDs, they should undergo testing under the supervision of a cardiac device specialist.

IMPROVING ROAD SAFETY ON THE NATIONAL ROAD NETWORK IN ROMANIA THROUGH PILOT SOLUTIONS

In recognition of outstanding work in the field of road safety, especially for the implementation of road safety pilot projects, N.C.R.I.A.-S.A. was declared the winner. The road safety pilot projects that have attracted the attention of the IRF, being a model to follow for all road administrations are: Roller Barriers; Impact attenuators; Road sector 2+1; Cable Road barriers; Illumination of dangerous sectors with light assemblies; Projects to increase road safety by creating elevated road crossings. The International Road Federation (IRF) encourages all companies and organizations in the road development sector to get involved in the awards program it grants, because by promoting innovative ideas a positive and motivating influence can be created. The National Company for Road Infrastructure Administration S.A, Traffic Safety Service participated in the "Find a Way Global Road Safety Award" organized by IRF. In this article, the road safety projects are presented, with their results and the road safety measures implemented by the national roads and highways administrator in Romania, so that other road administrations to be encouraged to implement as many road safety measures as possible.

Amplitude Based Pilot Protection for Transmission Line

Abstract: Distance protection and differential protection schemes are the two primary types of protection schemes employed in gearbox line protection today. However, industrial practice has shown that commonly used gap prevention techniques are limited in tripping speed and selectivity. The timing of the samples in each of the two relays located at the gearbox line terminals also affects the differential protection mechanism. On the other hand, pilot safety schemes using only the communication link to exchange local decision-making about fault conditions are not affected. These method include protection of Extra High Voltage (EHV) and Ultra High Voltage (UHV) transmission lines. Synchronization of time. The problem of creating a fast and accurate fault detection system for the safety of EHV/UHV transmission lines, which is crucial in present power systems, is the subject of this master's thesis. The protection method described in this thesis is the foundation for the detection and analysis of waves travelling wave along transmission at fault initiation. This method compares the arrival of the first traveling waves at both ends of the protected line with respect to direction. This will establish whether the fault is located in the safe zone or not. Based on high voltage transmission network safety requirements a suitable phase sequence algorithm is developed to control single phase tripping. Finally, through simulations conducted in the MATLAB environment, practical design concerns for incorporating the newly proposed protection algorithm into a numerical relay unit are investigated.

Phase I pilot safety and feasibility of a novel restraint device for critically ill patients requiring mechanical ventilation

Background: Mechanically ventilated Intensive Care Unit (ICU) patients often require wrist restraints, contributing to immobility and agitation, over-sedation, and delirium. The Exersides® Refraint® (Healthy Design, LLC), a novel restraint alternative, may be safe and facilitate greater mobility than traditional restraints. Objective: This National Institutes of Health Small Business Technology Transfer (STTR) Program Grant-funded single-site Phase I feasibility study evaluated Exersides® safety and feasibility in anticipation of a multi-site Phase II randomized controlled trial (RCT). Methods: In two academic ICUs, mechanically ventilated adults ⩾25 years old who were non-comatose, required restraints and had an expected stay of ⩾2 days were enrolled to wear Exersides® and traditional wrist restraints for 4 h on day 1, in a randomized order, and in the reverse order on day 2. Main outcomes were Exersides® safety (i.e., patient/clinician lacerations/injuries), feasibility (i.e., ⩾90% of required data collected), and patient/family/clinician feedback. Results: Eight patients were enrolled; one no longer required restraints at initiation, yielding seven subjects (median [interquartile range (IQR)] age 65 [55, 70] years, 86% men). All seven wore Exersides®, averaging (SD) 2.5 (1.0) hours per session, with no safety events reported. Across restraint time periods, 92% and 100% of Richmond Agitation-Sedation Scale (RASS) and wrist actigraphy data, respectively, were collected. Feedback was positive (more movement and comfortable than traditional restraints) and constructive (bulky, intimidating to apply). Conclusions: This pilot study provided key safety and feasibility data for a Phase II RCT evaluating Exersides® versus traditional wrist restraints. Feedback motivated minor device modifications before RCT initiation.

DESIGN AND PROTOTYPE OF AN AUTOMATED POSITIVE SUCTION MECHANICAL VENTILATOR UNDER AN ECONOMIC AND SOCIAL PROJECT ANALYSIS IN LOW-INCOME PATIENTS

The design and prototype of a low-cost portable positive pressure mechanical ventilator for use in cases of mass disasters and resource-limited environments are described. The ventilator provides breaths by compressing a conventional valve bag mask (AMBU) using a pivoting lever, eliminating the need for a human operator for the AMBU. An initial prototype was constructed using acrylic, with measurements of 285 x 350 x 250 mm and a weight of 4.1 kg (9 lb). It is powered by a 12V DC battery-operated electric motor and features an adjustable air volume of up to a maximum of 750 ml. Control is achieved through a human-machine interface using a 16x2 LCD screen displaying RPM and percentage speed data, which are adjusted using an easy-to-use potentiometer. The prototype also includes an overvoltage safety control mode and pilot lights to indicate the equipment's status. Iterations of the device will include a controllable inspiration-to-expiration time ratio, a pressure relief valve, and a battery bank system that allows for 4 hours of autonomy. The prototype manufacturing cost is only $820. Through this ventilator prototype, it is demonstrated that the lever-driven AMBU compression strategy is a viable option to achieve a low-cost, low-consumption portable technology that provides essential ventilator features at a fraction of the cost of existing technology

Group format psychedelic-assisted therapy interventions: Observations and impressions from the HOPE trial

AbstractBackgroundPsilocybin-assisted psychotherapy has demonstrated significant promise as a treatment for depression, anxiety, and existential distress associated with serious medical illness and has generally been employed on an individual basis, which presents challenges for scaling and resource availability. There are also compelling theoretical reasons to suggest that group-based formats-if utilized in a thoughtful fashion-might offer unique or enhanced therapeutic benefits for certain conditions or populations. The HOPE trial is an IRB-approved open-label feasibility and safety pilot study of psilocybin enhanced group therapy in patients with a DSM-5 depressive disorder associated with a cancer diagnosis completed at the Huntsman Cancer Institute (HCI) in Salt Lake City, Utah (HOPE: A Pilot Study of Psilocybin Enhanced Group Psychotherapy in Patients with Cancer). We report here qualitative survey-based data, impressions, and suggestions for group-based psychedelic-assisted therapy interventions based on our observations to inform future studies.MethodsPatients with a DSM-5 depressive disorder with an underlying cancer diagnosis were recruited from HCI by referral from oncology providers, palliative care, and social work. Following screening and consenting, 4-6 participants per cohort (with three total cohorts) were enrolled in a protocol involving 3 120 min group preparatory sessions, a single high-dose (25 mg) group psilocybin session, and 3 subsequent group integration sessions. Primary clinical outcomes are still in process of data collection and analysis. Qualitative data was gathered from patient written reports and a survey administered at 2 weeks post intervention. Qualitative reports were also gathered from the therapist team at a post-study group process session.FindingsWe report here results from a qualitative survey of participant experiences with group format study design, as well as impressions and guidelines for group format and group psychotherapeutic process to inform other studies pursuing group-based interventions in psychedelic therapy. Suggestions are provided for protocol design, screening processes, space considerations, therapist team structure, group process, music, timeline, as well as potential issues and challenges.

Health in the Skies: A Narrative Review of the Issues Faced by Commercial Airline Pilots.

While the health of airline pilots is crucial to ensuring the safe travel of millions of people worldwide, they remain vulnerable to a variety of health challenges due to the nature of their job. The purpose of this narrative review is to provide a comprehensive summary of the most common health issues experienced by commercial airline pilots. By examining the published literature on this topic, we sought to identify areas where further research is needed to understand better the health risks associated with being a pilot and to develop effective interventions to address these risks. We also highlight how recent technological advancesin digital health can be leveraged to conduct research into the potential usefulness of telehealth assessments for identifying occupational hazards in the aviation sector and providing targeted interventions. Overall, addressing the challenges of taking care of pilots' health and ensuring public safety will require a collaborative effort among airlines, governments, and regulators. Prioritizing pilot health and safety can actually improve profitability in the aviation sector by reducing costs associated with absenteeism, turnover, and accidents.

Modeling driver’s evasive behavior during safety–critical lane changes: Two-dimensional time-to-collision and deep reinforcement learning

Lane changes are complex driving behaviors and frequently involve safety–critical situations. This study aims to develop a lane-change-related evasive behavior model, which can facilitate the development of safety-aware traffic simulations and predictive collision avoidance systems. Large-scale connected vehicle data from the Safety Pilot Model Deployment (SPMD) program were used for this study. A new surrogate safety measure, two-dimensional time-to-collision (2D-TTC), was proposed to identify the safety–critical situations during lane changes. The validity of 2D-TTC was confirmed by showing a high correlation between the detected conflict risks and the archived crashes. A deep deterministic policy gradient (DDPG) algorithm, which could learn the sequential decision-making process over continuous action spaces, was used to model the evasive behaviors in the identified safety–critical situations. The results showed the superiority of the proposed model in replicating both the longitudinal and lateral evasive behaviors.

Multi-modal efficacy of a chimeric vesiculovirus expressing the Morreton glycoprotein in sarcoma

Vesiculoviruses are attractive oncolytic virus platforms due to their rapid replication, appreciable transgene capacity, broad tropism, limited preexisting immunity, and tumor selectivity through type I interferon response defects in malignant cells. We developed a synthetic chimeric virus (VMG) expressing the glycoprotein (G)from Morreton virus (MorV) and utilizing the remaining structural genes from vesicular stomatitis virus (VSV). VMG exhibited invitro efficacy by inducing oncolysis in a broad range of sarcoma subtypes across multiple species. Notably, all cell lines tested showed the ability of VMG to yield productive infection with rapid replication kinetics and inductionof apoptosis. Furthermore, pilot safety evaluations of VMG in immunocompetent, non-tumor-bearing mice showed an absence of toxicity with intranasal doses as high as 1e10 50% tissue culture infectious dose (TCID50)/kg. Locoregional administration of VMG invivo resulted in tumor reduction in an immunodeficient Ewing sarcoma xenograft at doses as low as 2e5 TCID50. In a murine syngeneic fibrosarcoma model, while no tumor inhibition was achieved with VMG, there was a robust induction of CD8+ Tcells within the tumor. The studies described herein establish the promising potential for VMG to be used as a novel oncolytic virotherapy platform with anticancer effects in sarcoma.

Can family-work conflict influence safety behavior in airline pilots? The mediating role of fatigue and the moderating role of extraversion

Airline pilot safety behavior is vital to inflight safety. Drawing upon the conservation of resources theory, this study examined whether family-work conflict (FWC) would influence airline pilot safety behavior, whether fatigue would mediate the link between FWC and safety behavior, and whether extraversion would play a moderating role in the relationships. Data were obtained by investigating a sample of 331 civil pilots and their supervisors from two Chinese airlines. The results showed that FWC negatively affected safety behavior (including safety compliance and safety participation), and fatigue played a mediating role in these relationships. Furthermore, the findings suggested that higher levels of extraversion mitigated the effect of FWC on fatigue, as well as the effect of FWC on safety compliance and safety participation. These findings demonstrated a deep understanding of the mechanisms by which FWC influences pilots’ safety behavior and contributed to occupational safety literature. Theoretical and practical implications, limitations, and future research directions are provided and discussed.

HPB P04 The DISSECT trial, ‘The effect of periaDventitIal SMA diSsECTion on margin status during pancreaticoduodenectomy for resectable pancreatic cancer’ Results of safety and feasibility pilot study

Abstract Background Survival following pancreatic cancer resection remains poor despite advances in adjuvant and neoadjuvant therapy. The incidence of positive margin status (R1) is high and an R1 resection is associated with poorer survival. The most commonly positive margin is the SMA, accounting for between 47–77% of R1 resections. Periadventitial dissection of the SMA includes the lymphoneural tissue around the adventitia in addition to the ‘mesopancreas’ in the resection specimen and is used to varying extent across different centres. Theoretically this technique should reduce R1 resection rate, however, there is a lack of prospective evidence in the published literature. Methods The DISSECT trial is a single centre, randomised control trial. All patients with a resectable as per NCCN staging criteria head of pancreas tumour are randomised to either ‘periadventitial SMA dissection’ or ‘no periadventitial SMA dissection’ (1:1 block randomisation, sealed envelope system). A standardised technique for length and circumference of dissection is used and intra-operative photography with blinded assessment of dissection status ensures quality control. This safety and feasibility stage assesses recruitment, technique and complications and will be followed by a study powered to detect the primary outcome of reduction in positive SMA margin status. Primary outcomes to be assessed in the fully powered study will be the SMA margin status as detailed by the AJCC 8th edition. Secondary outcomes are status of other margins, length of stay, complications, overall and disease-free survival, complications, and adjuvant treatment details. These are assessed prospectively by an investigator blinded to the study arm. Results For the feasibility stage, the following criteria were set to proceed: recruitment of 20 patients in 6 months, at least 80% of recruited patients to undergo correct arm of randomisation, and an increase in complication rate of no more than 10%. Within the first 6 months, 32 patients were successfully recruited and randomised. 6 were excluded post-randomisation but before SMA approach (N=2 cancelled and not re-booked, N=2 abandoned after opening, N=2 converted to total pancreatectomy). N=3 were eligible but not recruited, (2 refused after approach and 1 was missed due to research team capacity). N=25 (96.2%) underwent their allocated study arm (confirmed by blinded photo assessment). For potentially procedure related complications (SMA bleed, post-operative haemorrhage, chyle leak, collection, and anastomotic leak) there was an overall rate of 38.5%, with no significant difference between the 2 arms (42.9% in No SMA dissection arm and 33.3% in the SMA dissection arm). There were no incidences of SMA branch bleed in the SMA dissection arm and a single post-operative haemorrhage in the SMA dissection arm that was due to a mesenteric venous bleed. Conclusions The DISSECT trial is a randomised controlled trial that aims to evaluate the use of a standardised technique of periadventitial SMA dissection to reduce the rate of R1 resection in early stages of pancreatic cancer. The feasibility and safety pilot is complete and demonstrates successful recruitment and randomisation, excellent adherence to randomisation arm and no operative concerns from the surgical team. The study will now proceed to full recruitment with complications and blinded photo reviews for quality control assessed contemporaneously. Primary and secondary outcomes will be recorded prospectively by a member of the research team blinded to randomisation arm.

Esophageal Pressure Measurement in Acute Hypercapnic Respiratory Failure Due to Severe COPD Exacerbation Requiring NIV-A Pilot Safety Study.

Esophageal pressure (Pes) measurements could optimise ventilator parameters in acute respiratory failure (ARF) patients requiring noninvasive ventilation (NIV). Consequently, the objectives of our study were to evaluate the safety and accuracy of applying a Pes measuring protocol in ARF patients with AECOPD under NIV in our respiratory intermediate care unit (RICU). An observational cohort study was undertaken. The negative inspiratory swing of Pes (ΔPes) was measured: in an upright/supine position in the presence/absence of NIV at D1 (day of admission), D3 (3rd day of NIV), and DoD (day of discharge). A digital filter for artefact removal was developed. We included 15 patients. The maximum values for ∆Pes were recorded at admission (mean ∆Pes 23.2 cm H2O) in the supine position. ∆Pes decreased from D1 to D3 (p &lt; 0.05), the change being BMI-dependent (p &lt; 0.01). The addition of NIV decreased ∆Pes at D1 and D3 (p &lt; 0.01). The reduction of ∆Pes was more significant in the supine position at D1 (8.8 cm H2O, p &lt; 0.01). Under NIV, ∆Pes values remained higher in the supine versus upright position. Therefore, the measurement of Pes in AECOPD patients requiring NIV can be safely done in an RICU. Under NIV, ∆Pes reduction is most significant within the first 24 h of admission.

Takeoff runway overrun risk assessment in aviation safety based on human pilot behavioral characteristics from real flight data

Aviation safety is an important part of safety science and pilot behavior is a major factor in flight safety analysis. However, when analyzing unsafe events, such as runway overrun, majority of studies do not quantify the impact of pilot behavior on flight safety. The aim of this paper is to discover the pilot behavioral characteristics from actual flight data and apply them to construct a takeoff runway overrun risk assessment model. Concretely, the time series clustering is used to mine the pilot behavioral characteristics based on pilot operating data. Then, the similarity theory is introduced to construct a data-based man–machine-environment system expression including pilot behavioral characteristics to get the takeoff distance for the runway overrun risk assessment. The results of case study showed that 3 types of pilot behavioral characteristics were found in selected fleet, which mainly differ in the pilot reaction time after VR and operation input speed of the control column, and RO is more likely to happen under the combined influence of longer reaction time and slower operation input speed. The proposed method makes full use of real flight data from airlines under different conditions incorporating pilot behavior characteristics and can inform risk analysis of other unsafe events such as hard landing, tail strike, etc.

Lisdexamfetamine for the treatment of acute methamphetamine withdrawal: A pilot feasibility and safety trial

BackgroundThere is no effective treatment for methamphetamine withdrawal. This study aimed to determine the feasibility and safety of a tapering dose of lisdexamfetamine for the treatment of acute methamphetamine (MA) withdrawal. MethodsOpen-label, single-arm pilot study, in an inpatient drug and alcohol withdrawal unit assessing a tapering dose of oral lisdexamfetamine dimesylate commencing at 250 mg once daily, reducing by 50 mg per day to 50 mg on Day 5. Measures were assessed daily (days 0–7) with 21-day telephone follow-up. Feasibility was measured by the time taken to enrol the sample. Safety was the number of adverse events (AEs) by system organ class. Retention was the proportion to complete treatment. Other measures included the Treatment Satisfaction Questionnaire for Medication (TSQM), the Amphetamine Withdrawal Questionnaire and craving (Visual Analogue Scale). ResultsTen adults seeking inpatient treatment for MA withdrawal (9 male, median age 37.1 years [IQR 31.7–41.9]), diagnosed with MA use disorder were recruited. The trial was open for 126 days; enroling one participant every 12.6 days. Eight of ten participants completed treatment (Day 5). Two participants left treatment early. There were no treatment-related serious adverse events (SAEs). Forty-seven AEs were recorded, 17 (36%) of which were potentially causally related, all graded as mild severity. Acceptability of the study drug by TSQM was rated at 100% at treatment completion. Withdrawal severity and craving reduced through the admission. ConclusionA tapering dose regimen of lisdexamfetamine was safe and feasible for the treatment of acute methamphetamine withdrawal in an inpatient setting.

Predicting intersection crash frequency using connected vehicle data: A framework for geographical random forest

Accurate crash frequency prediction is critical for proactive safety management. The emerging connected vehicles technology provides us with a wealth of vehicular motion data, which enables a better connection between crash frequency and driving behaviors. However, appropriately dealing with the spatial dependence of crash frequency and multitudinous driving features has been a difficult but critical challenge in the prediction process. To this end, this study aims to investigate a new Artificial Intelligence technique called Geographical Random Forest (GRF) that can address spatial heterogeneity and retain all potential predictors. By harnessing more than 2.2 billion high-resolution connected vehicle Basic Safety Message (BSM) observations from the Safety Pilot Model Deployment in Ann Arbor, MI, 30 indicators of driving volatility are extracted, including speed, longitudinal and lateral acceleration, and yaw rate. The developed GRF was implemented to predict rear-end crash frequency at intersections. The results show that: 1) rear-end crashes are more likely to happen at intersections connecting minor roads compared to major roads; 2) a higher number of hard acceleration and deceleration events beyond two standard deviations in the longitudinal direction is a leading indicator of rear-end crashes; 3) the optimal GRF significantly outperforms Global Random Forest, with a 9% lower test error and a substantially better fit; and 4) geographical visualization of variable importance highlights the presence of spatial non-stationarity. The proposed framework can proactively identify at-risk intersections and alert drivers when leading indicators of driving volatility tend to worsen.

Research on the design and verification of the charging compatibility for electric vehicle ChaoJi charging

The international mainstream DC charging systems CHAdeMO 2.0 in Japan, GB/T 2015 in China, CCS1/CCS2 in Europe, and the U.S. have different control pilot circuit and the coupler designs. Control pilot circuit is an important component of the electric vehicle (EV) charging system and is used to monitor the function of the interaction between the EV and the electric vehicle supply equipment (EVSE). Existing system designs can make the difficult to achieve the compatibility between different charging systems, and reduce the user experience. This study first analyzes the practical applications of four existing mainstream DC charging systems. There are certain defects in structural design, safety, compatibility, and control pilot function, the introduction of a new generation of ChaoJi charging technology will change all these. Meanwhile the vehicle adapter design solution can perfectly solve the problem of physical compatibility between the existing charging system and ChaoJi vehicle. In addition, a new control pilot circuit design is proposed, to identify normal charging and abnormal states by hard node signals and states switches. By building a test environment, this new control pilot circuit has proven to its excellent characteristics in terms of fault monitoring, backward compatibility, and future-proof applications. ChaoJi charging technology has been adopted by CHAdeMO 3.0, laying the foundation for a globally harmonized charging system.

Incorporating driving volatility measures in safety performance functions: Improving safety at signalized intersections

About 40 percent of motor vehicle crashes in the US are related to intersections. To deal with such crashes, Safety Performance Functions (SPFs) are vital elements of the predictive methods used in the Highway Safety Manual. The predictions of crash frequencies and potential reductions due to countermeasures are based on exposure and geometric variables. However, the role of driving behavior factors, e.g., hard accelerations and declarations at intersections, which can lead to crashes, are not explicitly treated in SPFs. One way to capture driving behavior is to harness connected vehicle data and quantify performance at intersections in terms of driving volatility measures, i.e., rapid changes in speed and acceleration. According to recent studies, driving volatility is typically associated with higher risk and safety-critical events and can serve as a surrogate for driving behavior. This study incorporates driving volatility measures in the development of SPFs for four-leg signalized intersections. The Safety Pilot Model Deployment (SPMD) data containing over 125 million Basic Safety Messages generated by over 2,800 connected vehicles are harnessed and linked with the crash, traffic, and geometric data belonging to 102 signalized intersections in Ann Arbor, Michigan. The results show that including driving volatility measures in SPFs can reduce model bias and significantly enhances the models' goodness-of-fit and predictive performance. Technically, the best results were obtained by applying Bayesian hierarchical Negative Binomial Models, which account for spatial correlation between signalized intersections. The results of this study have implications for practitioners and transportation agencies about incorporating driving behavior factors in the development of SPFs for greater accuracy and measures that can potentially reduce volatile driving.

Multivariate analysis of car-following behavior data using a coupled hidden Markov model

Accurate analysis of driving behavior data is important for improving traffic operations and for automakers to design safe and effective Advanced Driver Assistance System (ADAS). Although different approaches have been proposed to analyze driving behavior data and understand the car-following behavior, very few of them have considered the interaction effects among driving behavior variables and constructed a multivariate modeling framework to fully understand and extract the underlying primitive driving patterns. To bridge this gap, this paper introduces the coupled hidden Markov model (CHMM) and evaluates its applicability in obtaining the car-following behavioral semantics and comparing the similarity of different drivers’ driving styles. The Safety Pilot Model Deployment (SPMD) dataset, which contains two years of naturalistic driving data, is used to demonstrate the advantages of the proposed coupled modeling approach. The modeling results suggest that CHMM with 3 hidden states provides the most appropriate driving behavior pattern segmentation results. It generates reasonable durations for each behavioral semantic by accounting for the dependence relationship among variables in the analysis. Moreover, a similarity analysis is conducted considering three aspects of a driving behavior pattern: driving behavior pattern transfer, driving behavior pattern selection, and aggressiveness behavior. The result reveals that these three aspects do not necessarily show consistent trends for the same driving behavior. Overall, the findings from this paper provide a novel framework for better understanding and interpreting the driving behavior and primitive driving patterns, and confirm the importance of considering the dependence among different driving behavior variables.

The Enhancing Error Management of Pilot and Line Operation Safety Audit

The Enhancing Error Management of Pilot and Line Operation Safety Audit