scholarly journals Building an Integrated Database of Road Design Elements

2020 ◽  
Author(s):  
Ali Dhafer Abed
Keyword(s):  
Road Network ◽  
Design Elements ◽  
Northern Iraq ◽  
The Road ◽  
Sight Distance ◽  
Sensing Technology ◽  
Design Speed ◽  
Stopping Sight Distance ◽  
City Structure ◽  
The City

The road network is the main artery within the city structure, which requires designing of routes and classification within the standards. Hence, the importance of this chapter, which will focus on the standards and design elements of the engineering design of road in terms of road type system, functional classification system, traffic volume system, number of traffic lane system, road width design, side slopes and elevations of road layers, super elevation, design speed, overtaking and stopping sight distance, longitudinal and cross sections of the road path, design elements of horizontal and vertical curves, and intersections. The Civil 3D Land Desktop, GIS programs, and remote sensing technology will be used to design the path of major highway linking two urban areas in Mosul (Northern Iraq), which will be considered a case study. The path of the road and its elements will be designed according to special criteria that are compatible with the topography and nature of the area. The geometric data of the road will then be exported with all the design elements to the GIS program to build an integrated road database. The database is capable of spatial analysis and connectivity with other parts of the road network in the city.

Operating Speed on Crest Vertical Curves with Limited Stopping Sight Distance

2000 ◽  
Vol 1701 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Daniel B. Fambro ◽  
Kay Fitzpatrick ◽  
Charles W. Russell
Keyword(s):  
Operating Speed ◽  
Design Elements ◽  
Geometric Data ◽  
A Value ◽  
Sight Distance ◽  
The Mean ◽  
The Difference ◽  
Design Speed ◽  
Stopping Sight Distance ◽  
The Relationship

Horizontal and vertical elements of a highway are designed based on an assumed design speed. This concept was developed in the 1930s as a mechanism for designing rural alignments to permit most drivers to operate uniformly at their desired speed. In 1938, AASHO recognized that drivers select a speed influenced by the roadway environment instead of an assumed design speed. Recent research suggests that design speed is no longer the speed adopted by the faster group of drivers but that it has become a value used to establish the sharpness of horizontal and vertical design elements. The objective of this study was to establish the relationship between design and operating speeds for crest vertical curves with limited sight distance. Geometric data and 3,500 paired speeds (speeds at control and crest sections) were collected at 36 sites in 3 states. The results indicated that both the 85th percentile and the mean operating speeds were well above the inferred design speeds of the crest vertical curves for the range of conditions studied and that the lower the design speed the larger the difference between the 85th percentile speed and the design speed. The mean reductions in speed between the control and crest sections tend to increase as available sight distance is decreased; however, the reduction in speed is less than that suggested by current AASHTO criteria.

scholarly journals IMPROVEMENT OF THE CITY TRANSPORT SYSTEM BY MEANS OF SIMULATION

2019 ◽  
Vol 8 (6) ◽  
Author(s):  
Polina A. Buyvol ◽  
Gulnara A. Yakupova ◽  
Irina V. Makarova
Keyword(s):  
Transport System ◽  
Traffic Management ◽  
Road Network ◽  
System Analysis ◽  
Computer Experiment ◽  
Simulation Models ◽  
Traffic Lights ◽  
The Road ◽  
Transport Services ◽  
The City

The transport system plays an important role in human activities and is an integral part of the successful functioning of the urbanized area. The increasing degree of provision of urban residents with transport services should at the same time keep the environment environmentally friendly and sustainable over time. The article is devoted to the issues of ensuring the rational functioning of the city transport system based on the development and implementation of an intelligent road infrastructure management system, the intellectual core of which are simulation models of problem areas of the road network. The objective of the study is the development of tools for organizing traffic in the conditions of the rapid growth of the fleet of vehicles. Research tasks were to analyze the research in the field of traffic management, to consider methods to reduce and prevent traffic jams on roads in general and in individual sections in particular. The following research methods were used: methods of system analysis, methods of modeling traffic flows, simulation, computer experiment. Achievements: the developed simulation model can be used to conduct a computer experiment in order to select the optimal parameters for the functioning of traffic lights on a specific section of the road network of the city of Naberezhnye Chelny

scholarly journals Towards a Rule-driven Approach for Updating Dynamic Road Segments

2012 ◽  
Vol 22 (6) ◽  
pp. 405-411
Author(s):  
Mohammad Reza Jelokhani-Niaraki ◽  
Ali Asghar Alesheikh ◽  
Abbas Alimohammadi ◽  
Abolghasem Sadeghi-Niaraki
Keyword(s):  
Data Model ◽  
Road Network ◽  
Road Maintenance ◽  
The Road ◽  
Dynamic Segmentation ◽  
Transportation Organization ◽  
Manual Tasks ◽  
The City ◽  
Transportation Applications ◽  
Road Segments

In recent years, the development of the GIS-T (Geographic Information System for Transportation) applications has gained much attention, providing the transportation planners and managers with in-depth knowledge to achieve better decisions. Needless to say, developing a successful GIS for transportation applications is highly dependent on the design of a well-structured data model. Dynamic segmentation (DS) data model is a popular one being used more and more for different GIS-T analyses, serving as a data model that splits linear features into new set of segments wherever its attributes change. In most cases, the sets of segments presenting a particular attribute change frequently. Transportation managers place great importance on having regular update and revision of segmented data to ensure correct and precise decisions are made. However, updating the segmented data manually is a difficult task and a time-consuming process to do, demanding an automatic approach. To alleviate this, the present study describes a rule-based method using topological concept to simply update road segments and replace the manual tasks that users are to carry out. The proposed approach was employed and implemented on real road network data of the City of Tehran provided by the Road Maintenance and Transportation Organization (RMTO) of Iran. The practical results demonstrated that the time, cost, human-type errors, and complexity involved in update tasks are all reduced. KEYWORDS: GIS-T, dynamic segmentation, segment, automatic update, change type, rule

Recopolis

2020 ◽  
Author(s):  
Lauro Olmo Enciso
Keyword(s):  
Urban Development ◽  
Social Inequality ◽  
Road Network ◽  
Hierarchical Organization ◽  
Rural Settlements ◽  
Medieval Period ◽  
The Road ◽  
Early Medieval Period ◽  
Industrial Buildings ◽  
The City

The foundation of the city of Recopolis on the initiative of King Liuvigild in ad 578 is the clearest material expression of the participation of the Visigothic state in urban development and in the creation of power landscapes. The ex novo construction of the city – city walls, palatial complex, elite houses, commercial and industrial buildings, hierarchical organization of space – and its impact on the wider territory, with the reorganization and renovation of the road network and creation of new rural settlements, was a clear demonstration of political prowess and an expression of the tax-collecting power of the state. Contextualizing these features within the broader landscape helps in understanding the spatial and social inequality that characterized the beginning of the early medieval period.

scholarly journals An Initial Investigation of the Effects of a Fully Automated Vehicle Fleet on Geometric Design

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
John Khoury ◽  
Kamar Amine ◽  
Rima Abi Saad
Keyword(s):  
Autonomous Vehicles ◽  
Autonomous Vehicle ◽  
Real Life ◽  
Geometric Design ◽  
Design Elements ◽  
Sight Distance ◽  
Human Driver ◽  
Projected Change ◽  
Vehicle Fleet ◽  
Stopping Sight Distance

This paper investigates the potential changes in the geometric design elements in response to a fully autonomous vehicle fleet. When autonomous vehicles completely replace conventional vehicles, the human driver will no longer be a concern. Currently, and for safety reasons, the human driver plays an inherent role in designing highway elements, which depend on the driver’s perception-reaction time, driver’s eye height, and other driver related parameters. This study focuses on the geometric design elements that will directly be affected by the replacement of the human driver with fully autonomous vehicles. Stopping sight distance, decision sight distance, and length of sag and crest vertical curves are geometric design elements directly affected by the projected change. Revised values for these design elements are presented and their effects are quantified using a real-life scenario. An existing roadway designed using current AASHTO standards has been redesigned with the revised values. Compared with the existing design, the proposed design shows significant economic and environmental improvements, given the elimination of the human driver.

Driver Perception–Brake Response in Stopping Sight Distance Situations

1998 ◽  
Vol 1628 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Daniel B. Fambro ◽  
Rodger J. Koppa ◽  
Dale L. Picha ◽  
Kay Fitzpatrick
Keyword(s):  
Response Time ◽  
Performance Studies ◽  
Response Times ◽  
Highway Design ◽  
Braking Performance ◽  
Reaction Distance ◽  
State Highway ◽  
Sight Distance ◽  
Design Speed ◽  
Stopping Sight Distance

One of the most important requirements in highway design is the provision of adequate stopping sight distance at every point along the roadway. At a minimum, this sight distance should be long enough to enable a vehicle traveling at or near the design speed to stop before reaching a stationary object in its path. Stopping sight distance is the sum of two components–brake reaction distance and braking distance. Brake reaction distance is based on the vehicle’s speed and the driver’s perception–brake reaction time (PBRT). Four separate, but coordinated, driver braking performance studies measured driver perception–brake response to several different stopping sight distance situations. The results from the driver braking performance studies suggest that the mean perception–brake response time to an unexpected object scenario under controlled and open road conditions is about 1.1 s. The 95th percentile perception–brake response times for these same conditions was 2.0 s. The findings from these studies are consistent with those in the literature: that is, most drivers are capable of responding to an unexpected hazard in the roadway in 2.0 s or less. Thus, the American Association of State Highway and Transportation Officials’ perception–brake response time of 2.5 s encompasses most of the driving population and is an appropriate value for highway design.

scholarly journals Development of the Road Network in the City of Salt in 2004 and 2016 Using GIS

2019 ◽  
Vol 13 (10) ◽  
pp. 94
Author(s):  
Deaa Al-Deen Amjad Qtaishat ◽  
Abd Al Azez Hdoush ◽  
Eng. Loiy Qasim Alzu’Bi
Keyword(s):  
Road Network ◽  
Population Distribution ◽  
Cognitive Model ◽  
Population Census ◽  
Network Characteristics ◽  
The Road ◽  
Standard Distance ◽  
Knowing That ◽  
The Social ◽  
The City

The aim of this study is to analyze the structure of the road network in As-Salt City in the period between 2004 and 2016, in order to identify the road employability in terms of the degree of connectivity, rotation, accessibility, and density. The relationship between the social properties and road distribution are also examined through analysis of the network characteristics concerning population distribution. The data used in this study was based on the As-Salt City Municipality Database supported with fieldwork done in 2016. The network analysis approach using GIS was used to calculate the roads employability. The study compares between the results of the analysis using the cognitive model of the road network for the years 2004 and 2016, knowing that the number of nodes in 2004 and 2016 was constant indicating the number of neighborhoods is 20, while the number of links changed from 42 links in 2004 to 50 links in 2016 and the average center of roads was determined, and it was estimated that the average road center is located near the municipality of As-Salt The study indicates that the road network suffers from a low degree of communication and rotation and the standard distance of road sites in the study area. The standard distance for each group was 2338.49 m. There is a disparity in the distribution of road network within As-Salt City, and the proportion of roads lengths dose not suit the population distribution pattern. The neighborhood of Al- Salalem, includes 19.5% of the total number of roads in As-Salt, because the neighborhood of Al-Salalem contains the highest population census and this is accompanied by urban growth, which is necessarily accompanied by the presence of roads. Therefore, it is recommended to have a plan to redistribute the population in the city and to establish new roads to reduce the problems of traffic in the city.

scholarly journals Data-Driven Bicycle Network Analysis Based on Traditional Counting Methods and GPS Traces from Smartphone

2019 ◽  
Author(s):  
Federico Rupi ◽  
Cristian Poliziani ◽  
Joerg Schweizer
Keyword(s):  
Road Network ◽  
Smartphone Application ◽  
The Road ◽  
Total Deviation ◽  
Deviation Index ◽  
Shortest Route ◽  
Gps Traces ◽  
The Absolute ◽  
The City ◽  
Entire Network

This research describes numerical methods to analyze the absolute transport demand of cyclists and then to quantify the road network weaknesses of a city with the aim to identify infrastructure improvements in favor of cyclists. The methods are based on a combination of bicycle counts and map-matched GPS traces and are demonstrated with the city of Bologna, Italy: the dataset is based on approximately 27,500 GPS traces from cyclists, recorded over a period of one month on a volunteer basis using a smartphone application. A first method estimates absolute, city-wide bicycle flows, by scaling map-matched bicycle flows of the entire network to manual and instrumental bicycle counts of the main bikeways of the city. As there is a good correlation between the two sources of flow data, the absolute bike-flows on the entire network have been correctly estimated. A second method describes a novel link-deviation index, which quantifies for each network edge the total deviation generated for cyclists in terms of extra distances traveled with respect to the shortest possible route. The deviations are accepted by cyclists either to avoid unpleasant road attributes along the shortest route or to experience more favorable road attributes along the chosen route. The link deviation index indicates the planner which road links are contributing most to the total deviation of all cyclists – in this way, repelling and attracting road attributes for cyclists can be identified. This is why the deviation index is of practical help to prioritize bike infrastructure construction on individual road network links.

scholarly journals Geometric Design of Highways for Accommodation of More Traffic Volume with Increased Design Speed

2018 ◽  
Vol 7 (3.12) ◽  
pp. 137
Author(s):  
S Srikiran ◽  
S Deepak Kumar ◽  
C Venkatasubramanian ◽  
D Muthu ◽  
S Suriyanarayanan
Keyword(s):  
Road Network ◽  
Critical Factor ◽  
Smooth Curve ◽  
Road Transport ◽  
Traffic Volume ◽  
Geometric Design ◽  
Highway Projects ◽  
The Road ◽  
The Government ◽  
Design Speed

Road transport plays an important role in India’s economy. It enables the country’s transportation sector to contribute 6.1% towards India’s GDP. The road network in our country is considered as a critical factor to the country’s development, social integration and security needs of the country. The Government of India has promoted foreign investments in highway projects to bring out high standards and quality. India’s road network carries over 65% of freight and 85% passenger traffic. The traffic volume carried by the national highways almost exceeds the designed traffic volume, and hence the desired speed cannot be achieved. Thus, widening of highways becomes necessary. The population growth is also to be considered and hence provision for future widening is to be provided. Our paper deal with the geometric design for widening of NH-9 is carried out using MX-Bentley software as per IRC specifications. This design includes horizontal and vertical profiling throughout the stretch of the road, according to the existing topographic data. The radius of the curve has been increased to make a smooth curve. Also, the vertical profile has been designed based on the allowable gradient and sight distances. From this, accommodation of more traffic volume and increment of design speed seems to be possible.

scholarly journals THE USE OF STATISTICAL MODELING TO ASSESS THE EFFECTIVENESS OF THE APPLICATION OF ADAPTIVE CONTROL AND RECONSTRUCTION OF THE ROAD NETWORK INTERSECTIONS

2021 ◽  
pp. 40-49
Author(s):  
Roman V. Andronov ◽  
◽  
Evgeny E. Leverents ◽  
Keyword(s):  
Statistical Modeling ◽  
Simulation Modeling ◽  
Traffic Management ◽  
Road Network ◽  
Economic Assessment ◽  
Adaptive Regulation ◽  
Network Nodes ◽  
The Road ◽  
Management Measures ◽  
The City

The article discusses the issues and results of the use of statistical modeling (one of the types of simulation modeling, the so-called "Monte Carlo" method), to assess the effectiveness of traffic management on the example of the Timofey Charkov st. and Verkhnetarmanskaya st. intersection, located in the city of Tyumen. The results are based on the length of the vehicle queue and traffic delay time for one car in the scenario of widening the intersection’s carriageway and/or the implementation of the adaptive regulation for traffic flows. The calculations were carried out in the "SmartAdaptive+" program developed by the authors, and designed for a technical and economic assessment of the effectiveness of traffic management measures and the use of adaptive regulation and measures to change the road network nodes configuration.

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