scholarly journals Assessing road segment impact on accessibility to critical services in case of a hazard

2019 ◽  
Author(s):  
Sophie Mossoux ◽  
Matthieu Kervyn ◽  
Frank Canters
Keyword(s):  
Emergency Services ◽  
Critical Infrastructure ◽  
Road Segment ◽  
Hazard Mapping ◽  
Hazard Maps ◽  
The Road ◽  
Hazardous Environments ◽  
Road Capacity ◽  
Risk Metric ◽  
New Infrastructure

Abstract. Development of hazard maps is one of the measures promoted by the international community to reduce risk. Hazard maps provide information about the probability of given areas to be affected by one or several hazards. As such they are useful tools to evaluate risk and support the development of safe policies. So far studies combining hazard mapping with accessibility to services are few. In hazardous environments, accessibility of the population to strategic infrastructure is important because emergency services and goods will principally be offered at or provided from these locations. If a road segment is blocked by a hazard, accessibility to services may be affected, or worse, people may be completely disconnected from specific services. The importance of each road segment in the transport network as a connecting element enabling access to relevant services is therefore critical information for the authorities. In this study, we propose a new application of hazard mapping which aims to define the importance of each road segment in the accessibility to services, taking in account the probability of being affected by a hazard. By iteratively removing one segment after the other from the road network, changes in accessibility to critical infrastructure are evaluated. Two metrics of road segment importance considering the population affected and the hazard probability are calculated for each segment: a road accessibility risk metric and a users' path vulnerability metric. Visualization of these road metrics is a useful way of valuing hazard maps and may help to support discussions about the development of new infrastructure, road capacity increase and maintenance of existing infrastructures, and evacuation procedures.

scholarly journals Assessing the impact of road segment obstruction on accessibility of critical services in case of a hazard

2019 ◽  
Vol 19 (6) ◽  
pp. 1251-1263 ◽  
Author(s):  
Sophie Mossoux ◽  
Matthieu Kervyn ◽  
Frank Canters
Keyword(s):  
Emergency Services ◽  
Critical Infrastructure ◽  
Road Segment ◽  
Hazard Mapping ◽  
Hazard Maps ◽  
The Road ◽  
Hazardous Environments ◽  
Risk Metric ◽  
The Impact ◽  
New Infrastructure

Abstract. Development of hazard maps is one of the measures promoted by the international community to reduce risk. Hazard maps provide information about the probability of given areas to be affected by one or several hazards. As such they are useful tools to evaluate risk and support the development of safe policies. So far studies combining hazard mapping with accessibility to services are few. In hazardous environments, accessibility of the population to strategic infrastructure is important because emergency services and goods will principally be offered at or provided from these locations. If a road segment is blocked by a hazard, accessibility to services may be affected, or worse, people may be completely disconnected from specific services. The importance of each road segment in the transport network as a connecting element enabling access to relevant services is therefore critical information for the authorities. In this study, we propose a new application of hazard mapping which aims to define the importance of each road segment in the accessibility to services, taking into account the probability of being affected by a hazard. By iteratively removing one segment after the other from the road network, changes in accessibility to critical infrastructure are evaluated. Two metrics of road segment importance considering the population affected and the hazard probability are calculated for each segment: a road accessibility risk metric and a users' path vulnerability metric. Visualization of these road metrics is a useful way of valuing hazard maps and may help to support discussions about the development of new infrastructure, road capacity increase and maintenance of existing infrastructures, and evacuation procedures.

Modeling and Estimation of Headway Distributions

1997 ◽  
Vol 1591 (1) ◽  
pp. 14-22 ◽  
Author(s):  
Serge P. Hoogendoorn ◽  
Hein Botma
Keyword(s):  
Estimation Method ◽  
Simulation Models ◽  
Independent Random Variables ◽  
Microscopic Simulation ◽  
Simple Analysis ◽  
Rural Roads ◽  
The Road ◽  
Road Capacity ◽  
Measurement Location ◽  
Fourier Series Analysis

A simple analysis to derive Branston’s generalized queueing model for (time-) headway distributions is presented. It is assumed that the total headway is the sum of two independent random variables: the empty zone and the free-flowing headway. The parameters of the model can be used to examine various characteristics of both the road (e.g., capacity) and driver-vehicle combinations (e.g., following behavior). Furthermore, the model can be applied to vehicle generation in microscopic simulation models and to safety analysis. To estimate the different parameters in the model, a new estimation method is proposed. This method, which was developed on the basis of Fourier-series analysis, was successfully applied to measurements collected on two-lane rural roads. The method was found to be both computationally less demanding and more robust than traditional parameter techniques procedures, such as maximum likelihood. In addition, the method provides more accurate results. Parameters in the model were examined with the developed estimation method. Estimates of these parameters at a specific period and a specific measurement location were to some extent transferable to other periods and locations. Application of the method to road capacity estimation is discussed.

scholarly journals Macroscopic dynamics and the collapse of urban traffic

2018 ◽  
Vol 115 (50) ◽  
pp. 12654-12661 ◽  
Author(s):  
Luis E. Olmos ◽  
Serdar Çolak ◽  
Sajjad Shafiei ◽  
Meead Saberi ◽  
Marta C. González
Keyword(s):  
Travel Time ◽  
Road Network ◽  
Spatial Dynamics ◽  
Urban Traffic ◽  
Nonequilibrium Phase Transition ◽  
Vehicle Miles Traveled ◽  
The Road ◽  
Road Capacity ◽  
Total Vehicle ◽  
The Individual

Stories of mega-jams that last tens of hours or even days appear not only in fiction but also in reality. In this context, it is important to characterize the collapse of the network, defined as the transition from a characteristic travel time to orders of magnitude longer for the same distance traveled. In this multicity study, we unravel this complex phenomenon under various conditions of demand and translate it to the travel time of the individual drivers. First, we start with the current conditions, showing that there is a characteristic time τ that takes a representative group of commuters to arrive at their destinations once their maximum density has been reached. While this time differs from city to city, it can be explained by Γ, defined as the ratio of the vehicle miles traveled to the total vehicle distance the road network can support per hour. Modifying Γ can improve τ and directly inform planning and infrastructure interventions. In this study we focus on measuring the vulnerability of the system by increasing the volume of cars in the network, keeping the road capacity and the empirical spatial dynamics from origins to destinations unchanged. We identify three states of urban traffic, separated by two distinctive transitions. The first one describes the appearance of the first bottlenecks and the second one the collapse of the system. This collapse is marked by a given number of commuters in each city and it is formally characterized by a nonequilibrium phase transition.

scholarly journals Geomorphological hazard analysis along the Egyptian Red Sea coast between Safaga and Quseir

2009 ◽  
Vol 9 (3) ◽  
pp. 751-766 ◽  
Author(s):  
A. M. Youssef ◽  
B. Pradhan ◽  
A. F. D. Gaber ◽  
M. F. Buchroithner
Keyword(s):  
Red Sea ◽  
Urban Areas ◽  
Natural Hazard ◽  
Hazard Analysis ◽  
Hazard Mapping ◽  
Hazard Maps ◽  
Industrial Facilities ◽  
Vulnerability Maps ◽  
Legal Restrictions ◽  
Sea Area

Abstract. Geomophological hazard assessment is an important component of natural hazard risk assessment. This paper presents GIS-based geomorphological hazard mapping in the Red Sea area between Safaga and Quseir, Egypt. This includes the integration of published geological, geomorphological, and other data into GIS, and generation of new map products, combining governmental concerns and legal restrictions. Detailed geomorphological hazard maps for flooding zones and earth movement potential, especially along the roads and railways, have been prepared. Further the paper illustrates the application of vulnerability maps dealing with the effect of hazard on urban areas, tourist villages, industrial facilities, quarries, and road networks. These maps can help to initiate appropriate measures to mitigate the probable hazards in the area.

scholarly journals Lane Change Behavior on Freeways: An Online Survey Using Video Clips

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
V. L. Knoop ◽  
M. Keyvan-Ekbatani ◽  
M. de Baat ◽  
H. Taale ◽  
S. P. Hoogendoorn
Keyword(s):  
Online Survey ◽  
Simulation Models ◽  
Lane Changes ◽  
The Road ◽  
Video Clips ◽  
Road Capacity ◽  
Change Behavior ◽  
Instrumented Vehicle ◽  
The Moment ◽  
The Right

Freeways form an important part of the road network. Yet, driving behavior on freeways, in particular lane changes and the relation with the choice of speed, is not well understood. To overcome this, an online survey has been carried out. Drivers were shown video clips, and after each clip they had to indicate what they would do after the moment the video stopped. A total of 1258 Dutch respondents completed the survey. The results show that most people have a strategy to choose a speed first and stick to that, which is the first strategy. A second, less often chosen, strategy is to choose a desired lane and adapt the speed based on the chosen lane. A third strategy, slightly less frequently chosen, is that drivers have a desired speed, but contrary to the first strategy, they increase this speed when they are in a different lane overtaking another driver. A small fraction have neither a desired speed nor a desired lane. Of the respondents 80% use the right lane if possible, and 80% avoid overtaking at the right. Also 80% give way to merging traffic. The survey was validated by 25 survey respondents also driving an instrumented vehicle. The strategies in this drive were similar to those in the survey. The findings of this work can be implemented in traffic simulation models, e.g., to determine road capacity and constraints in geometric design.

scholarly journals KAJIAN KINERJA PERSIMPANGAN TIDAK BERSINYAL (STUDI KASUS : PERSIMPANGAN TIGA GADUT, JALAN RAYA INDARUNG – BANDAR BUAT, KOTA PADANG)

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Eko Prayitno ◽  
Veronika Veronika
Keyword(s):  
Traffic Flow ◽  
Environmental Data ◽  
Degree Of Saturation ◽  
Road User ◽  
Total Delay ◽  
The Road ◽  
Traffic Conditions ◽  
Road Capacity ◽  
Side Friction Factor ◽  
Side Friction

The highway is one of the infrastructure for the smooth traffic. One part of the road that are considered necessary to be analyzed and evaluated is an intersection. Three Gadut intersection is non signalized intersection. The traffic flow is quite dense, and lack of discipline of road user factors competing space to pass the crossing, resulting in congestion is very influential on traffic conditions at peak hours in the morning, afternoon and evening. Prior to conducting the survey, the first to do is survey the condition of the intersection that includes geometric characteristics and traffic volume. From the analysis of environmental data, side friction factor to the junction of three Gadut is the criteria being. Rated capacity (C) the smallest is 3706.3 smp/hour, the degree of saturation of 1.1 smp/hour. This value is over the limit permitted values manually indonesian road capacity of 0.8 to 0.9 (1.1> 0.9), it is concluded that the traffic flow is the crossroads of three Gadut saturated traffic flow. The queue probability value between 128.8% - 157.4% with a total delay largest average 11.57 seconds/smp. It is concluded that the chances of a queue at the intersection of three Gadut very large, so it could cause congestion.

scholarly journals STUDI PERENCANAAN TEBAL PERKERASAN KONSTRUKSI JALAN RAYA (MENGGUNAKAN METODE BINA MARGA) PADA RUAS JALAN UMASUKAER DI KABUPATEN MALAKA

2019 ◽  
Vol 2 (1) ◽  
pp. 75
Author(s):  
Philipus Resato Nahak ◽  
Yosef Cahyo ◽  
Sigit Winarto
Keyword(s):  
Road Construction ◽  
Traffic Volume ◽  
Traffic Density ◽  
The Road ◽  
Technical Requirements ◽  
Road Section ◽  
Road Capacity ◽  
Data Survey ◽  
Pavement Thickness

The increase in traffic volume will cause a decrease in service due to decreased road capacity due to an increase in side constraints and due to the increase in traffic volume itself, which will ultimately cause the level of road saturation to increase. The situation occurred in the Umasukaer road section of the Malacca Regency. Therefore it is necessary to address improvements in the quality of the road in order to meet the feasibility of transportation facilities by taking into account the existing technical requirements. The results of planning found that through the 2015 LHR survey data with a prediction of an increase in traffic density of 6% per year, the LHR was obtained with a planned age of 7 years = 2540.7 vehicles/day/department and a 20-year plan life LHR = 5419.1 ked/day / major. The results of a gradual construction planning pavement study can be concluded that the planning model that has been designed is effective in strengthening road construction in accordance with existing technical requirements and efficient in terms of financing. The final results of gradual construction pavement thickness results are: Ashburton thickness (MS 744) = 8 cm, Ashburton (MS 744) = 13 cm, broken stone (CBR 100) = 20 cm, Sirtu (CBR 50) = 10 cm and CBR subgrade 5%. Pertambahan volume lalu lintas akan menyebabkan penurunan layanan diakibatkan menurunnya kapasitas jalan karena adanya peningkatan hambatan samping maupun karena beratambahnya volume lalu lintas itu sendiri yang pada akhirnya akan meyebabkan tingkat kejenuhan jalan meningkat. Keadaan tersebut terjadi ruas jalan Umasukaer Kabupaten Malaka, oleh karena itu perlu adanya penanganan perbaikan kualitas jalan agar memenuhi segi kelayakan sarana transportasi dengan memperhatikan syarat-syarat teknik yang ada. Hasil perencanaan didapatkan bahwa melalui data survey LHR tahun 2015 dengan prediksi peningkatan kepadatan lalu lintas sebesar 6% pertahun maka didapatkan LHR dengan umur rencana 7 tahun = 2540,7 kend/hr/jurusan dan LHR umur rencana 20 tahun = 5419,1 ked/hr/jurusan. Hasil studi perencanaan perkerasan konstruksi bertahap dapat diambil kesimpulan bahwa model perencaaan yang telah dirancang efektif dalam memperkerasa konstruksi jalan sesuai dengan syarat teknis yang ada serta efisien dalam hal pembiayaan. Hasil akhir tebal perkerasan konstruksi bertahap diperoleh hasil: Ketebalan Asbuton (MS 744) = 8 cm, Asbuton (MS 744) = 13 cm, batu pecah (CBR 100) = 20 cm, Sirtu (CBR 50) = 10 cm dan CBR tanah dasar 5%.

scholarly journals THE TRAFFIC VOLUME AND LEVEL OF SERVICE (LOS) OF UNIVERSITI PUTRA MALAYSIA (UPM) SERDANG CAMPUS MAIN ACCESS

2019 ◽  
Vol 17 ◽  
Author(s):  
Zakiah Ponrahono ◽  
Noorain Mohd Isa ◽  
Ahmad Zaharin Aris ◽  
Rosta Harun
Keyword(s):  
Traffic Flow ◽  
Traffic Congestion ◽  
Noise Pollution ◽  
Traffic Volume ◽  
Level Of Service ◽  
Idle Mode ◽  
The Road ◽  
Road Capacity ◽  
Motorized Vehicles ◽  
University Setting

The inbound and outbound traffic flow characteristic of a campus is an important physical component of overall university setting. The traffic circulation generated may create indirect effects on the environment such as, disturbance to lecturetime when traffic congestion occurs during peak-hours, loss of natural environment and greenery, degradation of the visual environment by improper or illegal parking, air pollution from motorized vehicles either moving or in idle mode due to traffic congestion, noise pollution, energy consumption, land use arrangement and health effects on the community of Universiti Putra Malaysia (UPM) Serdang. A traffic volume and Level of Service (LOS) study is required to facilitate better accessibility and improves the road capacity within the campus area. The purpose of this paper is to highlight the traffic volume and Level of Service of the main access the UPM Serdang campus. A traffic survey was conducted over three (3) weekdays during an active semester to understand the traffic flow pattern. The findings on traffic flow during peak hours are highlighted. The conclusions of on-campus traffic flow patterns are also drawn.

Combination of geomorphic classifiers through Machine Learning-based techniques for flood hazard assessment 

2021 ◽  
Author(s):  
Andrea Magnini ◽  
Michele Lombardi ◽  
Simone Persiano ◽  
Antonio Tirri ◽  
Francesco Lo Conti ◽  
...  
Keyword(s):  
Machine Learning ◽  
Hazard Assessment ◽  
Water Depth ◽  
Flood Hazard ◽  
Research Centre ◽  
Hazard Mapping ◽  
Hazard Maps ◽  
Flood Hazard Assessment ◽  
Flood Prone Areas ◽  
Flood Hazard Maps

<p><span xml:lang="EN-US" data-contrast="auto"><span>Every year flood events cause worldwide vast economic losses, as well as heavy social and environmental impacts, which have been steadily increasing for the last five decades due to the complex interaction between climate change and anthropogenic pressure (</span></span><span xml:lang="EN-US" data-contrast="auto"><span>i.e.</span></span><span xml:lang="EN-US" data-contrast="auto"><span> land-use and land-cover modifications). As a result, the body of literature on flood risk assessment is constantly and rapidly expanding, aiming at developing faster, computationally lighter and more efficient methods relative to the traditional and resource</span></span><span xml:lang="EN-US" data-contrast="auto"><span>-</span></span><span xml:lang="EN-US" data-contrast="auto"><span>intensive hydrodynamic numerical models. Recent and reliable fast-processing techniques for flood hazard assessment and mapping consider binary geomorphic classifiers retrieved from the analysis of Digital Elevation Models (DEMs). These procedures (termed herein “DEM-based methods”) produce binary maps distinguishing between floodable and non-floodable areas based on the comparison between the local value of the considered geomorphic classifier and a threshold, which in turn is calibrated against existing flood hazard maps. Previous studies have shown the reliability of DEM-based methods using a single binary classifier, they also highlighted that different classifiers are associated with different performance, depending on the geomorphological, climatic and hydrological characteristics of the study area. The present study maps flood-prone areas and predicts water depth associated with a given non-exceedance probability by combining several geomorphic classifiers and terrain features through regression trees and random forests. We focus on Northern Italy (c.a. 100000 km</span></span><sup><span xml:lang="EN-US" data-contrast="auto"><span>2</span></span></sup><span xml:lang="EN-US" data-contrast="auto"><span>, including Po, Adige, Brenta, Bacchiglione and Reno watersheds), and we consider the recently compiled MERIT (Multi-Error Removed Improved-Terrain) DEM, with 3sec-resolution (~90m at the Equator). We select the flood hazard maps provided by (</span></span><span xml:lang="EN-US" data-contrast="auto"><span>i</span></span><span xml:lang="EN-US" data-contrast="auto"><span>) the Italian Institute for Environmental Protection and Research (ISPRA), and (ii) the Joint Research Centre (JRC) of the European Commission as reference maps. Our findings (a) confirm the usefulness of machine learning techniques for improving univariate DEM-based flood hazard mapping, (b) enable a discussion on potential and limitations of the approach and (c) suggest promising pathways for further exploring DEM-based approaches for predicting a likely water depth distribution with flood-prone areas.</span></span><span> </span></p>

Investigation of Motorcycle Trajectories in 2-lane Horizontal Curves

2021 ◽  
Vol 16 ◽  
pp. 610-625
Author(s):  
Panagiotis Lemonakis
Keyword(s):  
Linear Equations ◽  
Great Accuracy ◽  
Design Guidelines ◽  
Road Segment ◽  
Small Radius ◽  
Horizontal Curve ◽  
Horizontal Alignment ◽  
The Road ◽  
Horizontal Curves ◽  
Traffic Lane

Most of the road design guidelines assume that the vehicles traverse a trajectory that coincides with the midline of the traffic lane. Based on this assumption the thresholds of various features are determined such as the maximum permissible side friction factor. It is therefore important to investigate the extent to which the trajectory of the vehicles is similar to the horizontal alignment of the road or substantial differences exist. To this end, a naturalistic riding study was designed and executed with the use of an instrumented motorcycle which measured the position of the motorcycle with great accuracy in a rural 2-lane road segment. The derived trajectories were then plotted against the horizontal alignment of the road and compared with the 3 consecutive elements which form a typical horizontal curve i.e., the entering spiral curve, the circular curve, and the exiting spiral curve. Linear equations were developed which correlate the traveled curvatures with the distance of each horizontal curve along the road segment under investigation. The process of the data revealed that the riders differ their trajectory compared to the alignment of the road. However, in small radius horizontal curves is more likely to observe curvatures that are similar to the geometric one. Moreover, the riders perform more abrupt maneuvres in the first part of the horizontal curves while they straighten the handlebars of the motorcycle before the end of the curve. The present paper aims to shed light on the behavior of motorcycle riders on horizontal curves and hence to contribute to the reduction of motorcycle accidents, particularly the single-vehicle ones.

Sign in / Sign up

Export Citation Format

Share Document