Environmental perception and monitoring play essential roles in maritime automation. Besides radar, the use of LiDAR for maritime surveillance has been increasing in recent years thanks to its high accuracy, high data density and good robustness against varying lighting conditions. This paper presents a novel approach for an adaptive shape-fitting technique using LiDAR point clouds in maritime applications, improving the object-tracking performance. The clustered LiDAR point clouds are fitted into bounding boxes or elliptic cylinders depending on their geometric shapes. A fitting score based on mean squared error is used for the shape decision. Afterwards, the extracted objects are associated with those in the past frames and tracked using an adaptive extended Kalman filter. The proposed algorithm is validated in simulation and post-processing using real-world test data. In simulations, the proposed adaptive shape-fitting technique shows a high object positioning and heading accuracy and guarantees a good object-tracking behaviour with a positioning error of 1.5 m. The proposed algorithm’s efficiency and robustness are further validated using test data recorded in the real-world using an unmanned surface vehicle equipped with LiDAR and GNSS in Rostock harbour, Germany. Test results show that the proposed adaptive shape-fitting technique helps the multi-object tracker reach a 2D position error of approximately 2 m with an update rate of 10 Hz, which is sufficient for object tracking in maritime applications. The size accuracy is improved by 10%, and heading accuracy is improved by 16% compared with multi-object tracking approaches only using L-shape fitting.

The inability to effectively and systematically identify and measure the damage in bridges will lead to an acceleration and dangerous deterioration of the health state of these structures. To repair and replace the aging and damaged bridge infrastructures, and prevent catastrophic bridge collapse, there is an urgent need to develop reliable, innovative, and efficient approaches to the performance assessment and inspection of bridges. Unmanned aerial vehicles, also knowns as drone, technology has found its way into a number of civilian applications including inspection in the last 20 years, predominantly due to lower cost and tangible scientific improvements. The intent of this paper is to map the current state-of- the-art drone-enabled bridge inspection practices and investigated their associated hazards and risks. This paper will integrate scenario prediction and, assess hazards as well as the social and environmental loss in the case of drone-enabled bridge inspection. Further, this paper will follow rather closely a three- phase process: hazard identification, hazard analysis, and hazard evaluation, all executed with qualitative data and methods by experts of a variety of fields, methodologies for recognition of the impact of cold operating environment on the performance of drone and drone-pilots, creative interpretation of the hazard factors of identifiable problems. The proposed preliminary hazard analysis (PHA) is exemplified via drone-enabled inspection of Håkenby bridge, which is located in the Viken county, in the eastern part of Norway.

The article overviews the influence transport supply has on the functioning parameters of the urban mobility structure of a large city that does not have off-street transport. The influence of the cost of paid parking, the length of bus and bike lanes on the share of trips by personal and public transport, cycling and pedestrian traffic is established. An assessment of the change in passenger traffic at individual bus stops and passenger traffic on bus routes is carried out with a change in the structure of urban mobility. The change in urban mobility with the expansion of the paid parking zone in the city centre is considered. The structure of urban mobility is determined using simulation modelling with a macroscopic transport model of a large city with a population over 800 thousand people. The parameters of three- factor mathematical models are determined, the adequacy of the models are checked and the static characteristics are presented. Changes in routes of movement of pedestrians and passengers of public transport after the construction of a new pedestrian bridge are predicted. Pedestrian traffic on the bridge increases with the introduction of a bus stop next to the bridge and two new routes for public transport.

As pedestrian networks tie together all transportation modes, their accessibility is crucial to supporting public transportation and fostering more sustainable and liveable cities. Nevertheless, most studies have relied on street networks when calculating pedestrian accessibility. While street networks can substitute for pedestrian networks in some cases, they fail to capture all paths available to pedestrians. Recent studies argue that this may distort our understanding of connectivity, accessibility and consequently the walkability of an area. This study sought to understand the effect of pedestrian network accessibility on segment-scale pedestrian density. To achieve this goal, dedicated pedestrian networks were constructed for two 400 m² areas in Bangkok and Osaka. In each site, the effect of accessibility variables, namely reach and gravity, were assessed first before controlling for other environmental factors addressing con- nectivity, transit proximity and path conditions. Measures were evaluated using ArcGIS and the Urban Network Analysis toolbox using data obtained from OpenStreetMap databases and field surveys. The results show that accessibility variables alone can account for up to 33% and 35% of observed pedes- trian densities in Bangkok and Osaka, respectively. Accessibility to retail land uses is the biggest driver in this relationship. However, when controlling for all variables, only in the denser, more connected Osaka site did accessibility to retail remain significant, helping to explaining up to 45% of observed pedestrian densities, while in Bangkok, its effect was minimal with proximity to rail transit being the only significant variable.

It is important for urban tourism development to focus on the accessibility of tourist points of interest (POIs). The spatial distribution of POIs should be closely linked to sustainable traffic development. In recent years, smartphones and global positioning systems have provided strong technical support for tourist POIs through social media. Many studies have been conducted to investigate the correlation between POIs and transportation from different perspectives. There is however a lack of quantitative research on the correlation between traffic accessibility and the distribution of urban tourist POIs using space syntax theory. This study proposes a method for optimizing the layout of tourist POIs based on traffic accessibility. We crawled 2,322 tourist POIs in Dalian as research objects, adopted kernel density estimation and constructed spatial syntax models. We analysed these models from the perspective of the spatial distribution characteristics of the POIs and traffic accessibility. The results showed no di- rect correlation between the spatial distribution of POIs and road networks. The conclusion is that the distribution of the most popular POIs does not coincide with the roads with the highest accessibility in Dalian. Therefore, we propose feasible optimization strategies for spatial planning of tourist POIs and sustainable traffic development.

Accessibility to public transportation system is a major concern in the cities of South Africa. The existing public transportation route network system offers poor accessibility from the residential areas to the public bus transportation nodes (bus stops/ranks) and vice versa in the cities of South Africa. Therefore, using the existing public bus transportation system in Durban, the objective of the study was to make a public transportation route network analysis to examine the accessibility of different areas in terms of walking distance and time to the public bus transportation network. A remote sensing-premised geographic information system method was used for the study. Findings suggested that different areas of the city are located at a distance between 0.5 km (0.31 mi) and 15 km (9.32 mi) from the public transport route networks. The inner-city areas including the central business districts that are located between 0.5 (0.31 mi) and 1.0 km (0.62 mi) are relatively more accessible in which people take a little above 8 minutes to a little above 16 minutes to reach a public transportation node. However, the areas located at a distance more than 15 km (9.32 mi) are highly inaccessible, and it takes more than 4 hours of walking to reach a node (bus stops). The study evidenced the current accessibility challenges in the public transport system in Durban, and the findings could assist in upgrading or re-configuring the route network system to make it more accessible.

Road traffic accidents are in the top ten of all deaths, with around 1.4 million fatalities and 50 million injuries per year worldwide. Regarding railways, in the EU, there were 1,666 serious accidents regis- tered in 2018 and 442 of them involved level crossings (LCs). The number of accidents on LCs in the EU in 2018 was approximately 27% of the total number of accidents on railways, but these accidents can be predictable and preventable. The current study investigated the efficiency of railways in terms of accident risk at LCs in 24 countries of the EU. The Data Envelopment Analysis (DEA) method has been applied to evaluate the efficiency of the selected railways in terms of safety at LCs. After extensive study of the subject, the comprehensive list of influencing factors has been identified and seven of them have been selected for further analysis. To investigate the relationship between selected factors and efficiency score of railways in terms of accident risk at LCs, the IBM SPSS software package has been deployed. The results show that GDP per capita and density of population in the selected countries have a strong influence on the efficiency of railways in terms of safety at LCs. The expected outcome of this research may contribute to a better understanding of the factors that influence the efficiency score of railways in term of accident risk at LCs and may help to develop preventative measures.