ORCID Profile
0000-0001-5439-7267
Current Organisation
Deakin University
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Publisher: Elsevier BV
Date: 12-2009
Publisher: Informa UK Limited
Date: 10-02-2021
Publisher: SAGE Publications
Date: 2009
DOI: 10.3141/2100-08
Abstract: Navigational collisions are one of the major safety concerns in many seaports. Despite the extent of work recently done on port navigational safety, little is known about harbor pilots’ perception of collision risks in port fairways. The study described in this paper used a hierarchical ordered probit model to investigate the associations between perceived risks and the geometric and traffic characteristics of fairways and pilot attributes. Perceived risk data, collected through a risk perception survey of Singapore port pilots, were used to calibrate the model. The intraclass correlation coefficient justified the use of the hierarchical model rather than an ordinary model. The results show higher perceived levels of risk in fairways attached to anchorages and in those featuring sharper bends and higher traffic operating speeds. Lower levels of risk were perceived in fairways attached to the shoreline and confined waters and in those with one-way traffic, a traffic separation scheme, cardinal marks, and isolated danger marks. The level of risk was also found to be perceived higher at night.
Publisher: Elsevier BV
Date: 09-2013
DOI: 10.1016/J.AAP.2013.04.014
Abstract: This paper explores the similarities and differences between bicycle and motorcycle crashes with other motor vehicles. If similar treatments can be effective for both bicycle and motorcycle crashes, then greater benefits in terms of crash costs saved may be possible for the same investment in treatments. To reduce the biases associated with under-reporting of these crashes to police, property damage and minor injury crashes were excluded. The most common crash type for both bicycles (31.1%) and motorcycles (24.5%) was intersection from adjacent approaches. Drivers of other vehicles were coded most at fault in the majority of two-unit bicycle (57.0%) and motorcycle crashes (62.7%). The crash types, patterns of fault and factors affecting fault were generally similar for bicycle and motorcycle crashes. This confirms the need to combat the factors contributing to failure of other drivers to yield right of way to two-wheelers, and suggest that some of these actions should prove beneficial to the safety of both motorized and non-motorized two-wheelers. In contrast, child bicyclists were more often at fault, particularly in crashes involving a vehicle leaving the driveway or footpath. The greater reporting of violations by riders and drivers in motorcycle crashes also deserves further investigation.
Publisher: Informa UK Limited
Date: 10-03-2020
Publisher: Elsevier BV
Date: 05-2013
Publisher: SAGE Publications
Date: 2011
DOI: 10.3141/2243-05
Abstract: Achieving sustainability is a major goal of many urban transport systems. To attain an efficient, safe, and sustainable transport system, many innovative policies have been attempted in the past. Those policies often require smart technologies to assist in the implementation process and to enhance effectiveness. This paper discusses how sustainability can be promoted by embedding smart technologies in a modern transport system. In particular, this paper studies the transport system of Singapore to see how it is addressing sustainability through the use of smart technologies. Various technological initiatives in managing traffic flow, monitoring and enforcement, sharing real-time information, and managing revenues are discussed in light of their potential to address sustainability issues. The Singapore experience provides a useful reference for cities that intend to develop and promote a sustainable transport system.
Publisher: Elsevier BV
Date: 11-2015
Publisher: SAGE Publications
Date: 20-04-2023
DOI: 10.1177/03611981231161349
Abstract: Although work zones pose risks to roadworkers and motorists, undertaking roadworks is important to maintain and upgrade road networks. Many researchers have examined the associations between safety levels and roadwork activities and have produced inconsistent findings. Whereas some researchers have compared safety levels before and during roadwork activities, few compared the safety levels at three stages of roadworks: before, during, and after roadworks, to obtain a comprehensive understanding of the associations. In addition to the inconsistent findings, another significant gap exists in the literature: existing research on all three stages is dated and scarce. To address this important gap, this paper aims to examine the associations between safety levels and three stages of roadworks. Using police-reported crash data from twenty-four high-speed road segments in the regional areas of New South Wales, Australia, this paper presents findings from a statistical analysis of the data to understand how crash rates and injury severity levels changed across the three stages. Results showed that crash rates for all crashes, as well as for fatal and injury crashes, reduced significantly from the before period to the during period, and then further to the after period. Greater reductions in crash rates were also observed for crashes that did not involve a heavy vehicle than the heavy vehicle-involved crashes, crashes that were not related to speeding or fatigue issues than those with such issues, crashes that occurred during weekdays than weekends, and crashes that occurred at straight sections than at curved sections.
Publisher: Cambridge University Press (CUP)
Date: 12-2010
DOI: 10.1017/S0373463309990233
Abstract: Navigational safety analysis relying on collision statistics is often h ered because of the low number of observations. A promising alternative approach that overcomes this problem is proposed in this paper. By analyzing critical vessel interactions this approach proactively measures collision risk in port waters. The proposed method is illustrated for quantitative measurement of collision risks in Singapore port fairways, and validated by examining correlations between the measured risks with those perceived by pilots. This method is an ethically appealing alternative to the collision-based analysis for fast, reliable and effective safety assessment, thus possessing great potential for managing collision risks in port waters.
Publisher: Elsevier BV
Date: 04-2014
Publisher: ACM
Date: 11-07-2023
Publisher: SAGE Publications
Date: 2016
DOI: 10.3141/2602-06
Abstract: The use of mobile phones while driving is increasing at an alarming rate despite the associated crash risks. A significant safety concern is that driving while distracted by a mobile phone is more prevalent among young drivers, a less experienced driving cohort with elevated crash risk. The objective of this study was to examine the gap acceptance behavior of distracted young drivers at roundabouts. The Center for Accident Research and Road Safety–Queensland Advanced Driving Simulator was used to test participants on a simulated gap acceptance scenario at roundabouts. Conflicting traffic approaching from the right of a four-legged roundabout was programmed to show a series of vehicles with the gaps between them proportionately increased from 2 s to 6 s. Thirty-two licensed young drivers drove the simulator under three phone conditions: baseline (no phone conversation), a hands-free phone conversation, and a handheld phone conversation. Results show that distracted drivers started responding to the gap acceptance scenario when they were closer to the roundabout and they approached the roundabout at slower speeds. These drivers also decelerated at faster rates to reduce their speeds before gap acceptance compared with nondistracted drivers. Although accepted gap sizes were not significantly different across phone conditions, differences in the safety margin at various gap sizes—measured by postencroachment time (PET) between the driven vehicle and the conflicting vehicle—were statistically significant across phone conditions. PETs for distracted drivers were smaller across different gap sizes and suggest that a smaller safety margin was accepted by distracted drivers compared with nondistracted drivers.
Publisher: Cambridge University Press (CUP)
Date: 10-07-2016
DOI: 10.1017/S0373463315000521
Abstract: Despite the extent of works done on modelling port water collisions, not much research effort has been devoted to modelling collisions at port anchorages. This paper aims to fill this important gap in the literature by applying the Navigation Traffic Conflict Technique (NTCT) to measuring the collision potentials in anchorages and for examining the factors contributing to collisions. Building on the principles of the NTCT, a collision potential measurement model and a collision potential prediction model were developed. These models were illustrated by using vessel movement data of the anchorages in Singapore port waters. Results showed that the measured collision potentials are in close agreement with those perceived by harbour pilots. Higher collision potentials were found in anchorages attached to the shoreline and international fairways, but not at those attached to confined water. Higher operating speeds, larger numbers of isolated danger marks and day conditions were associated with reduction in the collision potentials.
Publisher: SAGE Publications
Date: 2016
DOI: 10.3141/2587-01
Abstract: In multivehicle crashes involving motorcycles, the motorcycle rider is less likely to be at fault but more commonly severely injured than the other road user. Not surprisingly, crashes in which motorcycle riders were at fault and, particularly, crashes in which the other road users were injured have not received little research attention. This paper aims to address this gap in the literature by an investigation of the factors influencing the severity of injury to other road users in crashes in which the motorcyclist was at fault. Five years of data from Queensland, Australia, were obtained from a database of claims against the compulsory third party (CTP) injury insurance of the at-fault motorcyclists. Analysis of the data with an ordered profit model showed more severe injuries in crashes involving young (younger than 25) and older (older than 60) at-fault motorcyclists. Of the not-at-fault road users, the young, the old, and males were found to be more severely injured than were others. Injuries to vehicle occupants were less severe than those to motorcycle passengers. Crashes that occurred between vehicles traveling in opposite directions resulted in injuries that were more severe than injuries in crashes involving vehicles traveling in the same direction. While most existing studies have analyzed crash data reported by police, this study used CTP insurance data. Comparison of results indicates that CTP insurance data could be used as an alternative to crash data reported by police for gaining a better understanding of risk factors for motorcycle crashes and injury severity.
Publisher: Cambridge University Press (CUP)
Date: 12-09-2011
DOI: 10.1017/S0373463311000257
Abstract: Navigational collisions are one of the major safety concerns for many seaports. Despite the extent of work recently done on collision risk analysis in port waters, little is known about the influential factors of the risk. This paper develops a technique for modelling collision risks in port waterways in order to examine the associations between the risks and the geometric, traffic, and regulatory control characteristics of waterways. A binomial logistic model, which accounts for the correlations in the risks of a particular fairway at different time periods, is derived from traffic conflicts and calibrated for the Singapore port fairways. Results show that the fairways attached to shoreline, traffic intersection and international fairway attribute higher risks, whereas those attached to confined water and local fairway possess lower risks. Higher risks are also found in the fairways featuring higher degree of bend, lower depth of water, higher numbers of cardinal and isolated danger marks, higher density of moving ships and lower operating speed. The risks are also found to be higher at night.
Publisher: Elsevier BV
Date: 02-2015
Publisher: Elsevier BV
Date: 02-2012
Publisher: Elsevier BV
Date: 12-2016
DOI: 10.1016/J.AAP.2016.09.010
Abstract: Mandatory bicycle helmet laws have been found to increase helmet wearing rates in Australia and internationally. However, much of the research on factors influencing compliance with the Australian helmet laws is dated or focuses on commuters and city areas only. To address this gap, video recordings of bicycle riders were undertaken at 17 sites across Queensland, Australia, representing a mixture of on- and off-road locations, speed limits and regions. Helmet status was able to be determined for 98% of riders observed. The level of compliance with the laws was very high, with 98.3% of the more than 27,000 riders observed wearing helmets. Riders riding on roads were less compliant than those riding on bicycle paths, but no significant differences were observed between the school-holiday and school-term periods. Among the on-road riders, boys were less compliant than girls and overall children were less compliant than adults. Higher compliance levels were found for group riders, road bike riders, lycra-clad riders, during morning hours, and on 50km/h or lower speed limit roads. While the overall level of compliance was very high, certain subgroups were identified as a possible focus for interventions to further improve the compliance level, for ex le children (particularly boys) riding mountain bikes away from groups during the afternoon hours on 60km/h roads.
Publisher: Elsevier BV
Date: 12-2014
Location: Australia
No related grants have been discovered for Ashim Kumar Debnath.