Mathematical Models of Vehicular Speed on Mountain Roads

2000 ◽  
Vol 1701 (1) ◽  
pp. 104-110 ◽  
Author(s):  
Pedro Jose Andueza
Keyword(s):  
Mathematical Models ◽  
Design Procedure ◽  
Average Speed ◽  
The Road ◽  
Geometric Conditions ◽  
Sight Distance ◽  
Efficiency Measures ◽  
Vehicular Speed ◽  
On The Road ◽  
Design Speed

Mathematical models were developed to estimate vehicular speed on curves and tangents in mountain roads. The 85th percentile speed for curves was estimated by using the radius of the curve under consideration, the radius of the previous curve, sight distance in the curve, and tangent length before the curve. The average speed was calculated by using the radius of the curve under consideration, the radius of the previous curve, and sight distance. The 85th percentile and the average speed were estimated by using the radius of the previous curve and tangent length. Speeds adopted by drivers respond not to engineer’s design speed but to geometric characteristics of the road. A design procedure is proposed that takes advantage of available design speed and driver behavior on the road at the same time. On a curve, drivers consider two efficiency measures: speed and comfort. On some curves, they prefer to feel a certain degree of discomfort in exchange for obtaining greater speeds. For some geometric conditions, drivers adopt a speed that sacrifices not only comfort but also safety.

scholarly journals Analysis of Side Friction on Urban Arterials

2018 ◽  
Vol 19 (1) ◽  
pp. 21-30
Author(s):  
Pallavi Gulivindala ◽  
Arpan Mehar
Keyword(s):  
Traffic Volume ◽  
Combined Effects ◽  
Field Surveys ◽  
Average Speed ◽  
The Road ◽  
Vehicular Speed ◽  
On The Road ◽  
Side Friction ◽  
Friction Capacity ◽  
Combined Data

Abstract The influence of the side friction activities on the speed has been analyzed in the present study by conducting series of traffic field surveys. Pedestrian movements, parked vehicles and entry-exit of vehicles from surroundings, and wrong way movements are observed from videos and analyzed to estimate weighing factors. To examine the combined effects of all the activities the weighing factors are used to determine total value of side friction on the road. The study suggests model to estimate average speed of vehicular stream with the effect of side friction and volume on the roads section. It was found that the vehicular speed decreases as side friction increases at all the levels of traffic volume. However, no change in the speed was observed at lower level side friction. Capacity value obtained for combined data based on Greenshield’s theory that showed 9% reduction in the value considering with and without side friction.

Improved Design of Vertical Curves with Sight Distance Profiles

2003 ◽  
Vol 1851 (1) ◽  
pp. 13-24 ◽  
Author(s):  
Yasser Hassan
Keyword(s):  
Design Procedure ◽  
The United States ◽  
Analytical Models ◽  
Minimum Length ◽  
Vertical Alignment ◽  
The Road ◽  
Sight Distance ◽  
Special Cases ◽  
Current Design ◽  
Improved Design

Design of vertical alignment is one of the main tasks in highway geometric design. This task requires, among other things, that the designer ensure drivers always have a clear view of the road so they can stop before hitting an unexpected object in the road. Therefore, the ability to determine the required and available stopping sight distance (SSD) at any point of the vertical alignment is essential for the design process. Current design guides in the United States and Canada provide simple analytical models for determining the minimum length of a vertical curve that would satisfy the sight distance requirement. However, these models ignore the effect of grade on the required SSD. Alternative approaches and models have also been suggested but cover only special cases of vertical curves. Two specific models were expanded to determine the required SSD on crest and sag vertical curves. By comparing profiles of available SSD and required SSD on examples of vertical curves, it was shown that current North American design practices might yield segments of the vertical curve where the driver’s view is constrained to a distance shorter than the required SSD. An alternative design procedure based on the models was developed and used to determine the minimum lengths of crest and sag vertical curves. Depending on the approach grade, these new values of minimum curve length might be greater than or less than values obtained through conventional design procedures. Design aids were therefore provided in tabular form for designers’ easy and quick use.

scholarly journals Integration of kinematic and dynamic mathematical models of a two-axle electric car in the problem of estimating its stability on turns

ScienceRise ◽  
2021 ◽  
pp. 23-29
Author(s):  
Vadym Horeniuk
Keyword(s):  
Mathematical Models ◽  
Control Systems ◽  
Electric Drive ◽  
Internal Combustion Engines ◽  
Internal Combustion ◽  
Combustion Engines ◽  
The Road ◽  
On The Road ◽  
The Stability ◽  
Technological Product

Object of research: the process of movement of cars with internal combustion engines or the electric drive on a road curve. Investigation problem: assessment of the stability of cars with internal combustion engines or electric drive on a road curve and determination of conditions of its ensuring. The main scientific result. The article evaluated the stability of cars with internal combustion engines or electric drive on a road curve and determines the conditions of its ensuring using an algorithm that combines mathematical models of car movement on a road curve, synthesized based on balance equations of both kinematics and dynamics. The proposed models consider the change in speed of cars while driving on a road curve, and therefore belong to the class of differential equations. The analysis of these models allows calculating changes in time of values of limiting and critical speeds of movement of the car on a road curve. The article identifies the prospects of integration into this set of mathematical models another one, synthesized in the space of linguistic variables that characterize the uncertainty of the road surface and the degree of tire wear on different wheels of the car. The area of practical application of the research results: Automotive enterprises specializing in equipping cars with traffic control systems. Innovative technological product: A method of determining the limiting parameters of movement of the car on road curves, at which the car does not overturn while passing turns, and an algorithm for its implementation, which combines kinematic and dynamic mathematical models of car movement on the road curve. Scope of application of the innovative technological product: Equipping cars with additional control systems that assess the critical values of the traffic parameters on turns to ensure the conditions of non-overturning when the car passes these turns

Damage and cost simulation in pumped storm sewers

1979 ◽  
Vol 6 (1) ◽  
pp. 129-138
Author(s):  
E. H. Imam ◽  
J A McCorquodale ◽  
J K Bewtra
Keyword(s):  
Urban Areas ◽  
Damage Model ◽  
Design Procedure ◽  
Flow Simulation ◽  
Laboratory Model ◽  
Cost Models ◽  
The Road ◽  
Design Variables ◽  
Relaxation Procedure ◽  
On The Road

A flow-damage model has been developed to predict the annual probable damage due to basement and street floodings in relatively flat urban areas where pumping is required. The damage cost is obtained by integrating damages due to high as well as low probability storms. Annual capital recovery costs are also computed. The flow simulation is based on the Road Research Laboratory model, the Muskingum method, and a relaxation procedure for computation of surcharge conditions. The model can be used for design purposes or to evaluate existing systems. A suggested design procedure incorporating the flow-damage and installation cost models along with linear programming has been used to obtain an optimum design for a given pumped storm-sewer system. The optimal design is achieved when the combined cost of annual operating capital recovery, and annual probable damage is minimum. The design variables include the depths, slopes and diameters of the sewers. as well as sump area, rated pumping head, and discharge.

scholarly journals SIGHT DISTANCE ANALYSES IN ROAD DESIGN PROCESS: SERBIAN PRACTICE

Transport ◽  
2016 ◽  
Vol 31 (2) ◽  
pp. 250-259 ◽  
Author(s):  
Dejan Gavran ◽  
Sanja Fric ◽  
Vladan Ilić ◽  
Filip Trpčevski
Keyword(s):  
Cross Sections ◽  
3D Models ◽  
Software Tools ◽  
Design Parameters ◽  
Operating Speed ◽  
The Road ◽  
Road Design ◽  
Sight Distance ◽  
Road Geometry ◽  
Design Speed

New Serbian policies on road design introduce the concept of operating speeds. Decades ago, national policies were based on the constant design speed concept. Among other design parameters, in relation to that constant design speed, minimum radii of horizontal and vertical road geometry were determined. Introduction of the operating speed concept provides for more realistic prediction of speed levels along the road. Unlike the constant design speed, operating speed levels vary along the road, reaching higher levels in curves with larger radii, on straight sections and on reverse curves and dropping down to the design speed level in horizontal curves with the minimum radius. Consequently, besides a constant Stopping Sight Distance (SSD), which is calculated from the constant design speed, the new term, Required Sight Distance (RSD) is introduced. RSD varies along the road, as it is calculated from the operating speed, which also varies along the road. Appropriate RSD analyses are crucial on road rehabilitation projects, since a simple resurfacing that enables higher speed levels, without providing increased RSD, may hamper the safety of a newly resurfaced road. Software tools for predicting operating speed levels and optical analyses of the road are also presented in this paper. Software tools for RSD analyses enable the import of lines of sight into the 3D model of the roadway and their export into the cross sections extracted from the model, thus facilitating the obstacle removal. Also demonstrated are tools for determining Available Sight Distance (ASD), which are based on triangulated 3D models of the roadway as well.

scholarly journals Impact of Automated Truck Platooning on the Performance of Freeway Mixed Traffic Flow

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Seolyoung Lee ◽  
Cheol Oh ◽  
Gunwoo Lee
Keyword(s):  
Traffic Flow ◽  
Energy Savings ◽  
Automated Driving ◽  
Average Speed ◽  
The Road ◽  
Mobility Performance ◽  
Vehicle Platooning ◽  
Negative Effect ◽  
The Difference ◽  
On The Road

Vehicle platooning service through wireless communication and automated driving technology has become a reality. Vehicle platooning means that several vehicles travel like a train on the road with a minimum safety distance, which leads to the enhancement of safety, mobility, and energy savings. This study proposed a framework for exploring traffic mobility and safety performance due to the market penetration rate (MPR) of truck platoons based on microscopic traffic simulations. A platoon formation algorithm was developed and run on the VISSIM platform to simulate automated truck maneuvering. As a result of the mobility analysis, it was found that the difference in network mobility performance was not significant up to MPR 80%. Regarding the mobility performance of the truck-designated lane, it was found that the average speed was lower than in other lanes. In the truck-designated lane of the on-ramp section, the average speed was identified to be approximately 33% lower. From the viewpoint of network safety, increasing the MPR of the truck platoon has a positive effect on longitudinal safety but has a negative effect on lateral safety. The safety analysis of the truck-designated lane indicated that the speed difference by lane of MPR 100% is 2.5 times higher than that of MPR 0%. This study is meaningful in that it explores traffic flow performance on mobility and safety in the process of platoon formation. The outcomes of this study are expected to be utilized as fundamentals to support the novel traffic operation strategy in platooning environments.

scholarly journals Briefbeförderung des Ordens in Livland. Mit vorläufigen statistischen Bewertung

2021 ◽  
Vol 26 ◽  
pp. 73-90
Author(s):  
Juhan Kreem
Keyword(s):  
Statistical Analysis ◽  
Main Part ◽  
Average Speed ◽  
The Road ◽  
15Th Century ◽  
Delivery Routes ◽  
On The Road ◽  
In The Beginning ◽  
Calculated Average ◽  
Scarce Data

Delivery of Letters in the Teutonic Order in Livonia. With a preliminary statistical analysisThis contribution is on the organization and efficiency of the delivery of letters in the Teutonic Order in Livonia. Firstly, the scarce data on couriers is presented. Main part of the contribution is discussing the phenomenon of registration of time (hour) and place in some of the stations on the delivery routes of letters. This method, used extensively also in Prussia, was most likely introduced in Livonia in the beginning of the 15th century. It was used in case of most urgent letters and was first of all meant to monitor the efficiency of delivery. The majority of the places of registration of time are in the territory of the Order, but there are also some exceptions, when this was done in episcopal castles or manors. High number of letters of the Masters of the Teutonic Order in Tallinn City Archives is also allowing some preliminary statistical analysis, how the space and time was mastered on the route Riga-Wenden-Reval. It appears, that although the letters were ordered to be carried day and night, the calculated average speed is so low, that there were obviously made also some stops for rest on the road.

Hazy Glimpse Crook Virtual Assistant for Blind and Visual Impaired Community Healthcare

2020 ◽  
Vol 10 (10) ◽  
pp. 2501-2511
Author(s):  
Jilong Li ◽  
Memoona Mushtaq ◽  
Ayesha Mariam ◽  
Shehzad Khalid ◽  
Muhammad Ahsan Latif ◽  
...  
Keyword(s):  
Visually Impaired ◽  
Community Healthcare ◽  
Average Speed ◽  
The Road ◽  
The World ◽  
On The Road ◽  
Time Required ◽  
Blind Individuals ◽  
Vision Application ◽  
Impaired Individual

Innovations in the technologies are common and helpful for the visually impaired community. Visually impaired and blind individuals discover challenges in distinguishing barriers and obstacles. They hobble on the road that makes it hazardous. The reason for our responsibility is to offer solace to the visually vitiated individual by giving Hazy Glimpse Crook (HGC). It is a proposed answer for empowering the blind to recognize the world around them. With the assistance of a webcam, the picture of an obstacle is taken. After the digital image processed, a message will be created. From headphone's help, a visually impaired individual can discover the thing present in front of him. Inside the 70 cm scope, one ultrasonic sensor is utilized to recognize some other impediments around the client. While inside the scope of 80 cm, another sensor is set at the base of the stick. With the help of cautioning messages, it tells about puddles and all other obstacles. Additionally, from GPS blind's location can be tracked down. As they feel safe by using a stick, their average speed increases to twice. HGV (Hazy Glimpse Vision) application is our second part. In application talkback, any object recognizing and location of visually impaired can find out. The overall accuracy of Our HGC and HGV is approx. 96.87% in terms of the time required for an image to process.

Evaluation of Microwave Radar Trailers for Nonintrusive Traffic Measurements

2005 ◽  
Vol 1917 (1) ◽  
pp. 127-140 ◽  
Author(s):  
Helmut T. Zwahlen ◽  
Andrew Russ ◽  
Erdinc Oner ◽  
Meghna Parthasarathy
Keyword(s):  
Moving Average ◽  
Vehicle Classification ◽  
Validation Data ◽  
Average Speed ◽  
The Road ◽  
Microwave Radar ◽  
Time Period ◽  
Portable System ◽  
On The Road ◽  
Traffic Measurements

A trailer using two Wavetronix microwave radar units in side-fire mode was developed to measure traffic nonintrusively, including time-stamped arrival records, moving average speed ( N = 16), length, and classification (0 to 20 ft, 20 to 40 ft, more than 40 ft) of each vehicle. This paper reports on an initial validation of a prototype trailer on a four-lane section of US-50 east of Athens, Ohio. Traffic on the road was independently measured with video and radar, and the results were compared with records from the trailer to verify that the trailer was measuring the traffic with reasonable accuracy. The system records the arrival of more than 95% of all vehicles, with phantom and missed counts held to less than 5% in nearly all test cases. The overall average speed based on a 90-min time period is within 3 mph of the actual overall average values, although the observed standard deviation of the trailer moving average speed readings is about two to three times that of validation data, indicating that not all the variation is from traffic fluctuations. The vehicle classification is unreliable; the fraction of trucks in a lane can be severely overestimated or underestimated. The system needs further development to create a more reliable portable system for nonintrusive traffic measurements.

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.

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