Showing papers in "International journal of transportation science and technology in 2018"
TL;DR: The results of this study confirmed that WWD fatalities are more likely to be associated with head-on collisions and fatal WWD crashes tend to be involved with male drivers and off-peak hours.
Abstract: Wrong-way driving (WWD) has been a constant traffic safety problem in certain types of roads. These crashes are mostly associated with fatal or severe injuries. This study aims to determine associations between various factors in the WWD crashes. Past studies on WWD crashes used either descriptive statistics or logistic regression to identify the impact of key contributing factors on frequency and/or severity of crashes. Machine learning and data mining approaches are resourceful in determining interesting and non-trivial patterns from complex datasets. This study employed association rules ‘Eclat’ algorithm to determine the interactions between different factors that result in WWD crashes. This study analyzed five years (2010–2014) of Louisiana WWD crash data to perform the analysis. A broad definition of WWD crashes (both freeway exit ramp WWD crashes and median crossover WWD crashes on low speed roadways) was used in this study. The results of this study confirmed that WWD fatalities are more likely to be associated with head-on collisions. Additionally, fatal WWD crashes tend to be involved with male drivers and off-peak hours. Driver impairment was found as a critical factor among the top twenty rules. Despite several other studies identifying only the WWD contributing factors, this study determined several influencing patterns in WWD crashes. The findings can provide an excellent opportunity for state departments of transportation (DOTs) and local agencies to develop safety strategies and engineering solutions to tackle the issues associated with WWD crashes.
53 citations
TL;DR: The operational costs of the ADRTS showed to be in the same range of the current bus system, while providing a demand-responsive transport service with an average waiting time of around 4 minutes per passenger-trip and the economies of scale, which play an important role in public transport, are also apparent in the simulated ADR TS operations.
Abstract: The introduction of public transport services by fully automated vehicles can potentially change the way public transit services will be operated, as they allow shifting from rigid scheduled and route-bound services towards flexible, demand-responsive services. This study examines the potential performance of an Automated Demand Responsive Transport Service (ADRTS) as a replacement for scheduled bus services and simulates the effects of demand levels, vehicle capacity, vehicle dwell time and the initial vehicle distribution on system performance in terms of fleet size and system costs. The simulation tool allows simulating the operation of the ADRTS in a complete graph and is applied to the case study of Arnhem, the Netherlands. For this case study it has been shown that for a minimum fleet size following the imposed constraints, the operational costs range between 0.84 and 1.22 Euros and the average passenger wait time ranges between 2 and 6 minutes, according to the assumptions made on demand and operational parameters. The operational costs of the ADRTS showed to be in the same range of the current bus system, while providing a demand-responsive transport service with an average waiting time of around 4 minutes per passenger-trip. The economies of scale, which play an important role in public transport, are also apparent in the simulated ADRTS operations.
49 citations
TL;DR: In this paper, the authors focus on the estimation of the air transport footprint in terms of socioeconomic impacts in national economy and provide an essential decision support tool for strategic decisions about planning new air transport infrastructure, when resources are limited.
Abstract: Air transportation and economic development interact with each other as aviation makes significant direct and indirect contributions to the economy and increases the cycle of economic activity. Conventional wisdom is to provide an effective tool to provide quantitative estimations on the socioeconomic effects of air transport. This paper focuses on the estimation of the air transport footprint in terms of socioeconomic impacts in national economy. The socioeconomic effects assessment concept and methodology are given, providing an essential tool for planners, economists, analysts and researchers. The methodology concept and modelling approach provide essential benefits to support decisions on air transport infrastructures investments prioritization, fund allocation and sustainable strategic planning. The goal is to provide an essential decision support tool for strategic decisions about planning new air transport infrastructure, when resources are limited, in order to maximize the potential of social and economic development. The numerical application is Greece, which is a very attractive summer holiday tourist destination in southeast Mediterranean, suffering long time from economic stress. The results indicate that air transport is essential for Greece and thorough the last year’s economic downturn is resulting higher dependence to aviation mainly because the tourism and air transport linkage and the high spill-over effect of both industries to national economic model.
39 citations
TL;DR: Comparative analyses on drivers’ behavior during mandatory and discretionary lane changes by examining the statistical properties of four lane changing decision variables that describe the gaps between the subject vehicle and the surrounding vehicles show that, for the three decision variables associated with gaps in the target lane, the means and distributions are not significantly different.
Abstract: This research performs comparative analyses on drivers’ behavior during mandatory and discretionary lane changes. We do this by examining the statistical properties of four lane changing decision variables that describe the gaps between the subject vehicle and the surrounding vehicles. Mandatory and discretionary lane changes in NGSIM’s I-80 Freeway and U.S. Highway 101 data collection sites were identified. First, for each variable at the same site, descriptive statistics for the two types of lane changes were compared, and hypothesis tests on the difference between two means were conducted. Then, for each decision variable at the same site, the observed cumulative distributions between the mandatory and discretionary lane changes were compared by means of the Kolmogorov–Smirnov test. This test was repeated for the fitted distributions of the same decision variable at the same site. The results show that, for the three decision variables associated with gaps in the target lane, the means and distributions between the two types of lane changes are not significantly different. The only variable found to have significant differences in means and distributions is the gap between the subject vehicle and the preceding vehicle in the original lane. This may be because this variable is not an important input in mandatory lane change decisions. This finding provides statistical justification for researchers to develop models with different inputs for mandatory and discretionary lane changes in driver assist systems, in autonomous vehicles, and in microscopic traffic simulation tools.
36 citations
TL;DR: In this article, the authors investigated the potential of applying Cement fillers to asphalt pavement instead of mineral fillers, and they did a comprehensive study, including the raw materials properties tests, mix design, and verification of mixture performance.
Abstract: In order to investigate the potential of cement fillers applying in asphalt pavement instead of mineral fillers, this research did a comprehensive study, including the raw materials properties tests, mix design, and verification of mixture performance. Results show that in terms of the physical and volumetric properties, the cement fillers are similar with mineral fillers. The mix design process of asphalt mixture containing cement fillers can refer to the common asphalt mixture. The optimum asphalt/aggregate ratio was 5.0% for the materials and gradation selected in this research. The residual stability of immersion Marshall stability test was 78.9%, and the TSR of freeze–thaw splitting test was 74.4%. Both of them meet the specification requirements. The dynamic stability was 1169 time/mm, the seepage coefficient was 63.4 ml/min. These larger data than the required values demonstrated the good functional performance of asphalt mixture containing cement fillers, including the rutting resistance and the anti-permeable ability.
23 citations
TL;DR: In this paper, an evolution of the microstructure caused by long-term soiling processes and their effects on spatial and acoustic parameters of porous asphalt are analyzed, and the relationship between the geometry and the acoustic behavior is studied in great detail.
Abstract: Both spatial characteristics and the structure of air voids have certain impacts on the acoustic properties of porous asphalt, with regard to sound absorption behavior. Aside from global parameters of the microstructure, like porosity, certain geometrical characteristics of air voids also have an effect on sound absorption and acoustic parameters. Spatial parameters of the microstructure like 3D fractal dimension or pore diameter distributions are determined from X-ray CT scans, using methods of digital image processing. Geometrical parameters of different porous asphalt samples are compared, and the relationship between the geometry and the acoustic behavior is studied in great detail. In particular, an evolution of the microstructure caused by long-term soiling processes – changes which usually materialize during porous asphalt’s service life – and their effects on spatial and acoustic parameters are analyzed. A defined laboratory procedure for artificial soiling has been used to study soiling mechanisms, enabling the correlation to certain soiling states to be drawn. The design of the study shows how more basic analyses of the acoustic deterioration of porous asphalt due to soiling effects during its service life are possible, with the consideration of changes in the air void microstructure.
21 citations
TL;DR: In this article, the authors proposed a basic model which can be applied to both permeable asphalt pavements and permeable concrete pavements to evaluate their environmental impacts and compared them with dense-graded asphalt pavement.
Abstract: In recent years, urban flooding has occurred frequently in different cities in China. This has caused huge economic and environmental damages. As one of the main elements in the concept of sponge city – a potential solution to this problem – permeable pavements have attracted great attentions. This new technology has the ability to mitigate urban flooding effectively and it also provides other environmental benefits. Life Cycle Assessment (LCA) is a newly developed evaluation approach that can be applied to estimate the environmental impacts of pervious pavements in the entire life cycle. This study propose a basic model which can be applied to both permeable asphalt pavements and permeable concrete pavements to evaluate their environmental impacts. The impacts of this technology are investigated on urban flooding, water recycling and water purification. Then a comparison between permeable asphalt pavement and dense-graded asphalt pavement is conducted for a typical four-lane secondary road. Results indicate that in 10 km of the modeled road, 49TJ of energy consumption, 6700 t of equivalent carbon dioxide emissions, 0.1 t of lead emissions and 1 t of zinc emissions can be avoided if the permeable pavements is used. Moreover, the most significant reduction in energy consumption, GHG emissions, lead emissions and zinc emissions occurs in the use phase.
19 citations
TL;DR: A comparison between locally weighted regression and a social force model in real data suggests superior performance of the data driven model on modeling pedestrian movements, but a more integrated comparative analysis should be conducted, to validate these preliminary observations.
Abstract: This paper presents a comparison and relative assessment of data driven techniques and conventional theoretical pedestrian simulation models. Data driven methods are applied for simulating phenomena without a priori knowledge of parameter connections, while indicating high modeling performance. In contrast, theoretical models rely on pedestrian kinematics principles and provide mathematical functions on model parameters. A comparison between locally weighted regression and a social force model in real data (collected by the authors within the framework of this research) suggests superior performance of the data driven model on modeling pedestrian movements. However, a more integrated comparative analysis should be conducted, to validate these preliminary observations. Additional contributions, presented in this research, include an algorithm for eliminating data noise, based on an Unscented Kalman filter and moving average extensions.
18 citations
TL;DR: In this paper, the authors explored the extent of the economic recession to the Greek passenger and freight road transport system, and compared the trends between the Greek transport system and the average European one.
Abstract: The transport sector is closely related to the economy of a country. This mainly applies to urban areas, which play an essential economic role in a country’s GDP. According to the EC’s Green Paper 2007 for urban mobility, approximately 1% of the EU’s GDP is annually lost due to the increased passenger and freight flow demands in city centres and its consequent impacts (e.g. pollution, delay, etc.). Since the beginning of the economic crisis in 2008 the economies of many countries were affected and their transport sectors encountered a serious decline. On this basis, the principal aim of this paper is to explore the extent of the economic recession to the Greek passenger and freight road transport system. European transport data is exploited to compare the trends between the Greek transport system and the average European one. The analysis determines the key elements that influence road transport focusing on freight and passenger movement by identifying potential relationships between transport performance and socioeconomic factors.
13 citations
TL;DR: In this article, the relationship between the continuously changed temperature and the relative crack opening in asphalt base course by analyzing the data collected from an in-service asphalt pavement was determined, and the authors made direct statements about the deformation conditions occurring in an asphalt base layer as a result of temperature.
Abstract: Asphalt pavement is known to be deteriorated by the repetitive traffic loading, climatic condition, aging of asphalt mixture etc. after opening to traffic. Crack plays a critical role in pavement deterioration. Several studies have been conducted to obtain a better understanding with respect to climate related pavement fracture behavior. However, the limitation of the previous researches was that most of them were conducted by laboratory experiment or numerical simulation. The main objective of this study is to determine the relationship between the continuously changed temperature and the relative crack opening in asphalt base course by analyzing the data collected from an in-service asphalt pavement. To achieve this objective, four artificial transverse cracks were first induced on the asphalt subbase of a test track, and then their temperatures and crack opening were recorded by monitoring systems. Diurnal and annual trends of temperature and relative crack opening as well as their relationship were investigated and discussed. In this study, a test track with defined asphalt layers was constructed, which was specially equipped with sensors that continuously monitored the temperatures and opening widths of structural cracks in the test track. On the basis of the findings obtained, it is possible for the first time to make direct statements about the deformation conditions occurring in an asphalt base layer as a result of temperature.
13 citations
TL;DR: Results show that drivers of less-than-truckload (LTL) shipments, weekend shipments, and older drivers have significantly fewer challenges finding safe and adequate parking.
Abstract: This paper focuses on the availability of parking for freight vehicles, with a specific focus on being able to find safe and adequate parking (i.e., a designated parking location for large trucks) along a primary freight corridor in Oregon. This is achieved through the use of a truck driver survey regarding their experiences related to the availability of safe and adequate parking. The survey is geographically focused on drivers and freight activity throughout the Pacific Northwest, as to better infer on truck parking along the study corridor. The data and information collected are then utilized to estimate a binary outcome (logit) model to evaluate how different factors, obtained from the driver survey, impact the likelihood of finding safe and adequate parking from the perspective of the driver. Of 134 indicator variables, 11 factors are found to be statistically significant and provide insights into what impacts or affects the probability that a driver will encounter problems finding safe and adequate parking. Results show that drivers of less-than-truckload (LTL) shipments, weekend shipments, and older drivers have significantly fewer challenges finding safe and adequate parking. Findings from the current study can be used to better guide efforts in Oregon, and across the country, in regard to safe and adequate truck parking.
TL;DR: A reliable method called the Automated Vehicle Delay Estimation Technique (AVDET), which automatically estimates delay at a signalized intersection using detector data and signal timing information from the existing traffic signal controller, is developed and tested.
Abstract: Vehicle delay is one of the most important performance measures of effectiveness (PMOE) in intersection traffic operations. It allows traffic engineers to evaluate the performance of a traffic system component or the effectiveness of the system-wide control strategy. It is often utilized for real-time applications such as adaptive signal control, congestion management, and dynamic traffic assignment. However, obtaining intersection performance data in real time such as intersection control delay can be very time consuming and labor intensive. This paper develops and tests a reliable method called the Automated Vehicle Delay Estimation Technique (AVDET), which automatically estimates delay at a signalized intersection using detector data and signal timing information from the existing traffic signal controller. Results from the delay estimation algorithm were compared with those from simulation, followed by statistical tests under varying traffic operation conditions. The findings showed that AVDET was able to provide effective results under different traffic and signal control scenarios. Future work of field implementation for the proposed algorithms is recommended to investigate the model reliability and effectiveness in real-time traffic conditions.
TL;DR: In this paper, the authors defined urban safety as two aspects: to against traffic accidents and urban crime, and the results based on the GIS and the statistical analysis tells us that there are many common factors affecting the occurrence of traffic accident and the urban violence/crime in total.
Abstract: In this study, we define urban safety as two aspects: to against traffic accidents and urban crime. In a general view, Japan has been ranked as one of the least fatalities countries by the traffic safety statistics as well as one of the least crime rate countries by the crime statistics. Therefore, Japan is widely evaluated as one of the safest countries in the world. In this study, Toyota City is chosen to understand the hidden factors affecting urban safety. Toyota Motor Corporation, one of the biggest automobile manufacturers in the world, locates its headquarters and shapes the car-oriented society in Toyota City. The results based on the GIS and the statistical analysis tells us that there are many common factors affecting the occurrence of traffic accidents and the urban violence/crime in total. The detailed analysis focusing on narrow streets, theft case and the land used for residents is found having negative effects on both traffic accidents and urban crime. Such result from the research gives us some hints to make the urban planning and urban management much effectively and consequently make the urban lives much safer.
TL;DR: The disparity between good street design practice and highway design standards with respect to walkability is assessed and amendments and additions that would enhance the walkability element in the design of new schemes and the retrofitting of existing ones are proposed.
Abstract: This study assesses the disparity between good street design practice and highway design standards with respect to walkability. Using an example local network in the commune of Lorentzweiler in Luxembourg, the study first performs a large-scale network-level walkability evaluation using the well-established Pedestrian Environment Review System (PERS) pedestrian audit method in order to identify design shortcomings around the network. Then, focusing on the shortcomings identified, the study evaluates the findings with respect to the existing highway design standards of Luxembourg, highlights gaps in the latter and proposes amendments and additions that would enhance the walkability element in the design of new schemes and the retrofitting of existing ones.
TL;DR: The focus of the project was the development of a multi-layered wearing course system with a synthetic top layer, representing optimized texture-properties and a synthetically-bound bottom layer functioning as an absorption layer that shows a level difference of tire-road noise of more than 8 dB(A) regardless of the speed.
Abstract: To facilitate modern economies, the development of society and the extension of economic areas the traffic sector plays a leading role by supplying a technically functioning, efficient and environmentally compatible infrastructure. Due to the increase of transportation processes, especially the commercial transport, the mode of transport “road” is of great importance in this regard. However, this causes a steadily increasing exposure of the population to traffic-induced emissions – especially noise emissions have received more attention in recent years! Public infrastructure construction is subjected to numerous attempts aiming to standardize the tasks as well as the limitation of costs. The result has been that the innovation potential, especially in regard to designs limiting traffic noise, has not been made use of sufficiently. Furthermore, the performance limit of conventional materials has almost been reached which is why this research project developed and designed a completely new surface-material concept based on synthetic materials. The surface-system was designed to exhibit the highest possible acoustically favorable properties, was verified by examinations in the Vehicle-Pavement Interaction Facility of the Federal Highway Research Institute (BASt) and was constructed in-situ. The focus of the project was the development of a multi-layered wearing course system with a synthetic top layer, representing optimized texture-properties and a synthetically-bound bottom layer functioning as an absorption layer. In addition to the acoustic efficacy of such a wearing course system, the structural feasibility as well as the durability of the concept are subjects of the analysis. Over all the concept shows a level difference of tire-road noise of more than 8 dB(A) regardless of the speed – this is almost a half of the perceived volume. The presented results are converted into further development steps to facilitate transfer of the idea into a marketable product. This further development is carried out within the framework of the research project “Fundamental research on polymer materials and innovative production and installation technologies for road surface layer systems (INNO PAVE)” funded by the Federal Ministry of the Education and Research. In addition to the RWTH Aachen University, represented by the Chair and Institute of Highway Engineering Aachen, an interdisciplinary team from science, research and industry is involved in this further development, which will be finalized in 2018. The described work symbolizes the initial basis for this.
TL;DR: In this article, the influence of temperature variations on airfield jointed plain concrete pavement (JPCP) deflections is studied and the results indicate that the temperature change slightly affects the deflection basin at the centre of a slab unless the positive temperature gradient in the slab increases to exceed a certain critical value.
Abstract: This paper aims to study the influences of temperature variations on airfield jointed plain concrete pavement (JPCP) deflections. The maximum deflection at the transverse joint ( D 0 j ), the maximum deflection at the corner of a slab ( D 0 c ), and the deflection basin at the centre of a slab were considered. The in-situ deflection measurements at three civil airports were conducted over a 24-hour period and numerical simulations for JPCP at a civil airport were performed as well. The results indicate that the temperature change slightly affects the deflection basin at the centre of a slab unless the positive temperature gradient in the slab increases to exceed a certain critical value. But both D 0 j and D 0 c are significantly affected by temperature variations. The results of in-situ tests show that D 0 j (or D 0 c ) is almost stable from 1 pm and 5 pm in a day. At other times of one day, there is a strong negative liner correlation between D 0 j (or D 0 c ) and the pavement surface temperature during the heating period and the cooling period, respectively. The results of numerical simulations reveal that both D 0 j and D 0 c gradually increase with the increase of the average temperature. The results of numerical simulations also suggest that a critical negative/positive temperature gradient exists at the transverse joint while there is a critical positive temperature gradient at the slab corner. Besides, all the critical temperature gradients are seldom affected by the average temperature. When the temperature gradient exceeds the critical value, D 0 j , D 0 c and all values of the deflection basin have a strong positive linear correlation with the temperature gradient.
TL;DR: A rapid algorithm for finding the best combination of signaling phases and their optimal timings which minimize the total delay of the entire period based on the multiple-period analysis proposed in Highway Capacity Manual 2010 is formulated.
Abstract: Traffic signal optimization for both traffic plan design and signal timing is a task that demands significant time and computational resources. In this paper, we formulate a rapid algorithm for finding the best combination of signaling phases and their optimal timings which minimize the total delay of the entire period based on the multiple-period analysis proposed in Highway Capacity Manual 2010. The optimization problem is solved in MATLAB using two optimization algorithms: the genetic and the scatter search algorithms. Comparative evaluation of the algorithms in relation to their estimation time and their solutions was performed at a reference intersection. The estimated time-dependent delay was calibrated and validated in AIMSUN microsimulation software for the base conditions and the optimized plans. The comparison of the global optimal solution of the two algorithms and the true global optimal was performed through a computational experiment in a two approach intersection with proper discretization of the variables. The results showed that the scatter search algorithm is superior to the genetic algorithm with respect to the required runtime and the estimated optimal solution.
TL;DR: In this paper, the authors investigated the impact of carbon pricing on ticket prices, airlines' market shares and resulting networkwide carbon emissions via a methodology which includes a supply and demand model and a method for estimating carbon emissions costs by airline and itinerary.
Abstract: In this paper, the introduction of a carbon pricing policy in air transport industry is investigated. The impact on ticket prices, airlines’ market shares and resulting network-wide carbon emissions is studied via a methodology which includes a supply and demand model and a method for estimating carbon emissions costs by airline and itinerary. The application of the carbon pricing policy at the U.S. domestic aviation network revealed that the policy could have some significant effects on ticket prices, air travel demand and resulting CO2 emissions for high carbon price. But, to achieve the aviation industry ambitious goal to reduce net aviation CO2 emissions by 50% until 2050, this paper suggests that airlines and policy makers need to adopt a multi-faceted approach with carbon pricing policies, technological, operational and infrastructure improvements to ensure economic and environmental sustainability.
TL;DR: In this paper, the authors compare organizational safety culture and working conditions in Norwegian cargo and passenger transport at sea, and examine safety outcomes (safety behaviours and crewmember accidents) of safety culture, and discuss how safety culture is influenced by the framework conditions of the the passenger and the cargo sectors.
Abstract: Seafaring is among the most hazardous occupations, and more knowledge is needed to inform preventive measures. One way of developing such knowledge is to compare different sub-sectors, to shed light on factors influencing occupational safety. Previous research has indicated a higher risk of serious occupational injuries in coastal cargo transport compared to passenger transport, hypothesizing that this could be due to the safety culture in coastal cargo transport. The aims of the present paper are to: (1) Compare organizational safety culture and working conditions in Norwegian cargo and passenger transport at sea, (2) Examine safety outcomes (safety behaviours and crewmember accidents) of safety culture and working conditions in the passenger and the cargo sector, and (3) discuss how safety culture and working conditions are influenced by the framework conditions of the the passenger and the cargo sector. The study is based on a small-scale survey to crewmembers on vessels registered in the Norwegian Ship Register (NOR), both at passenger vessels (N = 84) and coastal cargo vessels (N = 73). Results indicate that crew members in the coastal cargo sector experience more work pressure, and that they rate their organizational safety culture as lower than respondents in the passenger transport sector. Moreover, results indicate that work pressure and poor organizational safety culture are closely related to unsafe working behaviours, which in turn is associated with personal injuries on board. However, as a positive organizational safety culture is related to safer working behaviours, future research should examine how organizational safety culture can be employed to reduce the impact of negative framework conditions in maritime transport on occupational safety.