scholarly journals Modelling the Operating Speed in Segments of Two-Lane Highways from Probe Vehicle Data: A Stochastic Frontier Approach

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
António Lobo ◽  
Marco Amorim ◽  
Carlos Rodrigues ◽  
António Couto
Keyword(s):  
Stochastic Frontier ◽  
Operating Speed ◽  
Design Elements ◽  
New Model ◽  
Horizontal Curves ◽  
Probe Vehicle ◽  
Vehicle Data ◽  
Road Planning ◽  
Design Consistency ◽  
Definition Of

Most of the existing operating speed statistical models are applicable to individual design elements, particularly horizontal curves and tangents. A segment approach to operating speed has rarely been followed, with a few exceptions mainly related to the performance assessment of urban and freeway corridors, or design consistency studies using speed profiles built from successive design elements. This study introduces a new model to predict operating speeds in segments of two-lane highways. The maximum operating speed is given by a stochastic frontier function of the average daily traffic and road geometrics; the asymmetric disturbance accounts for the diversity in drivers’ behaviour and vehicle characteristics, allowing estimating any percentile speed. The model was calibrated using probe vehicle data from noncongested roads. The accuracy of the average daily traffic in representing the actual driving conditions was further validated using simultaneous speed-traffic measurements. The new model aims to assist practitioners in the evaluation of design consistency from a macroscopic perspective since the early stages of road planning and design, as well as to support the definition of speed limits at new or existing infrastructures.

scholarly journals Empirical Speed Behavior on Horizontal Ramp Curves in Interchanges in the Netherlands

2017 ◽  
Vol 2618 (1) ◽  
pp. 38-47 ◽  
Author(s):  
Haneen Farah ◽  
Aries van Beinum ◽  
Winnie Daamen
Keyword(s):  
The Netherlands ◽  
Prediction Models ◽  
Operating Speed ◽  
Trajectory Data ◽  
Design Elements ◽  
The Road ◽  
Road Design ◽  
Speed Prediction ◽  
Design Consistency ◽  
High Level

Several studies in the literature have indicated that interchanges are the most crash-prone areas within the motorway system in number and severity of accidents. The reason is the high level of turbulence as a result of vehicle lane changes and speed variability. To understand the safety consequences of an interchange design (e.g., type of connecting ramps, radii and superelevation of curves, and lane and shoulder widths), an in-depth investigation of driving speed behavior is needed. Such an investigation requires the collection of detailed trajectory data on vehicles on different interchanges. These types of data are rarely available, and as a result, such studies are scarce in the literature. The main objective of this present study was to analyze driver speed behavior on different ramps at interchanges, and to develop an operating speed prediction model as a function of the road design elements. Trajectory data on free-moving vehicles were derived from stabilized video images taken from a camera mounted underneath a helicopter, which hovered over the road areas studied. Data were collected from 29 curves at six freeway–freeway interchanges in the Netherlands. The sample included nine direct connections, 12 semidirect connections, and eight indirect connections. The findings showed that speeds were affected by several road geometric characteristics of the curves, by driver expectancy and design consistency, and by the percentage of trucks in traffic. The operating speed prediction models developed in the study will provide designers with tools to estimate the operating speed during the design process.

Evaluating Horizontal Alignment Design Consistency of Two-Lane Rural Highways: Development of New Procedure

2000 ◽  
Vol 1737 (1) ◽  
pp. 9-17 ◽  
Author(s):  
John McFadden ◽  
Lily Elefteriadou
Keyword(s):  
Primary Objective ◽  
Maximum Speed ◽  
Operating Speed ◽  
Speed Profile ◽  
Horizontal Curve ◽  
Rural Highways ◽  
Speed Reduction ◽  
Design Elements ◽  
The Difference ◽  
Design Consistency

Design consistency refers to the condition wherein the roadway geometry does not violate driver expectations. Operating-speed profile models are used to evaluate the consistency of a design by identifying locations with large speed variability between successive design elements. There is a direct correlation between safety and variability in speeds. Recent operating-speed models predict the 85th percentile speeds on horizontal curves and compare this value with the expected 85th percentile speed on the approach tangent. There is a direct correlation between speed variability between successive design elements and crash rates. Eighty-fifth percentile speeds, however, do not necessarily represent the speed reductions experienced by drivers. The primary objective of the research was to assess the efficacy of the use of 85th percentile speed by operating-speed profile models to evaluate the consistency of a design. Speed data were collected at 21 horizontal curve sites. These data were used to evaluate the implication of using 85th percentile speed for evaluating design consistency. A new parameter was investigated for analyzing design consistency: the 85th percentile maximum reduction in speed (85MSR). This parameter is calculated by using each driver’s speed profile from an approach tangent through a horizontal curve and determining the maximum speed reduction each driver experiences. These maximum speed reductions are sorted, and the 85th percentile value becomes the statistic of interest, or 85MSR. 85MSR was compared with the difference in 85th percentile speeds (85S), and it was found that 85MSR is significantly larger than 85S. The data showed that, on average, 85MSR is approximately two times larger than 85S. Models were developed that predict 85MSR as a function of geometric design elements, and these models could be used to complement existing operating-speed models.

Operating speed models for two-lane rural roads in Pakistan

2008 ◽  
Vol 35 (5) ◽  
pp. 443-453 ◽  
Author(s):  
Rizwan A. Memon ◽  
G. B. Khaskheli ◽  
A. Sami Qureshi
Keyword(s):  
Global Positioning System ◽  
Prediction Models ◽  
Geometric Design ◽  
Operating Speed ◽  
Rural Roads ◽  
Horizontal Curves ◽  
Measuring Devices ◽  
Global Positioning ◽  
Speed Prediction ◽  
Design Consistency

One of the suitable techniques used to improve safety on roads is to check the consistency of geometric design. The concept of design consistency has emerged worldwide, but no research has been found to date on design consistency in Pakistan. The most common parameter for the evaluation of design consistency is operating speed. Several models have been developed to predict operating speed on two-lane rural roads. However, these models were based on spot speed data collected through traditional speed measuring devices. This study uses continuous speed profile data collected using a vehicle equipped with a VBox (a global positioning system based device). Eleven test sections were selected in two provinces of Pakistan (i.e., Sindh and Balochistan). Driver behavior is also studied in the present research. Models were developed for prediction of operating speed on horizontal curves and on tangents. Validation of the developed models shows compatibility with the experimental data; hence, the developed speed prediction models can be used to evaluate the geometric design consistency of two-lane rural roads in Pakistan.

scholarly journals OPERATING SPEED PREDICTION MODEL AS A TOOL FOR CONSISTENCY BASED GEOMETRIC DESIGN OF FOUR-LANE DIVIDED HIGHWAYS

Transport ◽  
2019 ◽  
Vol 34 (4) ◽  
pp. 425-436 ◽  
Author(s):  
Gourab Sil ◽  
Avijit Maji ◽  
Suresh Nama ◽  
Akhilesh Kumar Maurya
Keyword(s):  
Prediction Model ◽  
Lateral Position ◽  
Geometric Design ◽  
Operating Speed ◽  
Vehicle Speed ◽  
Horizontal Curve ◽  
Passenger Cars ◽  
Horizontal Curves ◽  
Speed Prediction ◽  
Design Consistency

Researchers have studied two-lane rural highways to predict the operating speed on horizontal curves and correlated it with safety. However, the driving characteristics of four-lane-divided highways are different. Weak lane discipline is observed in these facilities, which influences vehicle speed in adjacent lane or space. So, irrespective of its lane or lateral position, vehicles in four-lane divided highways are considered free flowing only when it maintains the minimum threshold headway from any lead vehicle. Examination of two conditions is proposed to ensure the free flow. Vehicles meeting both conditions, when tracked from the preceding tangent section till the centre of the horizontal curve, are considered as free flowing. The speed data of such free flowing passenger cars at the centre of eighteen horizontal curves on four-lane divided highways is analysed to develop a linear operating speed prediction model. The developed model depends on curve radius and preceding tangent length. The operating speed of passenger car in four-lane divided highways is influenced by horizontal curve of radius 360 m or less. Further, longer tangent would yield higher operating speed at the centre of the curve. Finally, two nomograms are suggested for conventional design, consistency based design and geometric design consistency evaluation of four-lane divided horizontal curves.

scholarly journals EXPERIMENTAL RELATIONSHIPS BETWEEN OPERATING SPEEDS OF SUCCESSIVE ROAD DESIGN ELEMENTS IN TWO-LANE RURAL HIGHWAYS

Transport ◽  
2015 ◽  
Vol 32 (2) ◽  
pp. 138-145 ◽  
Author(s):  
Laura Eboli ◽  
Giuseppe Guido ◽  
Gabriella Mazzulla ◽  
Giuseppe Pungillo
Keyword(s):  
Road Traffic ◽  
Characteristic Curve ◽  
Geometric Characteristic ◽  
Operating Speed ◽  
Rural Highways ◽  
Design Elements ◽  
Road Design ◽  
Long Time ◽  
Independent Variable ◽  
Design Consistency

Speed has been identified for a long time as a key risk factor in road traffic. Inappropriate speeds contribute to a relevant part of road crashes, and then to the mortality and disabilities resulting from them. Starting from this consideration this paper investigates road safety by analysing operating speed, which is the 85th percentile speed. Particularly, two regression models are proposed to predict operating speeds for different road elements related to specific road conditions. The case study is represented by a two-lane rural highway. Smartphone-equipped vehicles were used to evaluate the operating speed for each element of the analysed road segment. Continuous speed data were recorded by the vehicles driven by users with different driving behaviours. Since the lack of safety is often linked to an inconsistency roadway geometric design, we effected a preliminary quantitative design consistency evaluation that confirmed the need of having accurate experimental measures of operating speed or appropriate models for predicting it. We propose two types of operating speed models: one for estimating speed profiles for horizontal curves, and the other one for tangents. According to both models, operating speed is predicted by the combination of an independent variable representing a geometric characteristic (curve radius for the curves and length for the tangent elements) and an independent variable relating to the speed, and specifically the operating speed of the previous road element. The models show a good predictive capability, and can be considered as a useful tool for operators and technicians for road management.

scholarly journals Beyond Classical Definition: The Non-definition of Gamification

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Mario S. Staller ◽  
Swen Koerner
Keyword(s):  
Empirical Investigation ◽  
Working Life ◽  
Pedagogical Practice ◽  
Police Recruits ◽  
Design Elements ◽  
The Subject ◽  
Anchor Points ◽  
The One ◽  
Definition Of ◽  
Game Elements

AbstractGamification is regularly defined as the use of game elements in non-gaming contexts. However, discussions in the context of the pedagogical value of gamification suggest controversies on various levels. While on the one hand, the potential is seen in the design of joyful learning environments, critics point out the pedagogical dangers or the problems related to optimizing working life. It becomes apparent that the assumptions guiding action on the subject matter of gamification in educational contexts differ, which leads to different derivations for pedagogical practice—but also allows for different perspectives on initially controversial positions. Being aware of these assumptions is the claim of a reflexive pedagogy. With regard to the pedagogical use of gamifying elements and their empirical investigation, there are three main anchor points to consider from a reflexive stance: (a) the high context-specificity of the teaching undertaken and (b) the (non-)visibility of the design elements and (c) the (non-)acceptance of the gamified elements by the students. We start by providing a discussion of the definitional discourse on what is understood as gamification leading to our argument for a non-definition of gamification. We describe the potential of this non-definition of gamification and exemplify its use in a gamified concept of teaching police recruits professional reflexivity. The concept features the narrative of a potential crime that has been undertaken and that students decide for themselves if they want to engage with it.

scholarly journals Review of Studies on Older Drivers’ Behavior and Stress—Methods, Results, and Outlook

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3503
Author(s):  
Yanning Zhao ◽  
Toshiyuki Yamamoto
Keyword(s):  
Age Groups ◽  
Older Drivers ◽  
Driving Simulators ◽  
Driving Experience ◽  
Older Driver ◽  
Vehicle Data ◽  
Vehicle Systems ◽  
Questionnaire Surveys ◽  
Definition Of ◽  
Short Time

This paper presents a review on relevant studies and reports related to older drivers’ behavior and stress. Questionnaires, simulators, and on-road/in-vehicle systems are used to collect driving data in most studies. In addition, research either directly compares older drivers and the other drivers or considers participants according to various age groups. Nevertheless, the definition of ‘older driver’ varies not only across studies but also across different government reports. Although questionnaire surveys are widely used to affordably obtain massive data in a short time, they lack objectivity. In contrast, biomedical information can increase the reliability of a driving stress assessment when collected in environments such as driving simulators and on-road experiments. Various studies determined that driving behavior and stress remain stable regardless of age, whereas others reported degradation of driving abilities and increased driving stress among older drivers. Instead of age, many researchers recommended considering other influencing factors, such as gender, living area, and driving experience. To mitigate bias in findings, this literature review suggests a hybrid method by applying surveys and collecting on-road/in-vehicle data.

Approach to Quantify the Impact of Disruptions on Traffic Conditions using Dynamic Weighted Resilience Metrics of Transport Networks

2021 ◽  
pp. 036119812199866 ◽  
Author(s):  
Elise Henry ◽  
Angelo Furno ◽  
Nour-Eddin El Faouzi
Keyword(s):  
Three Dimensional ◽  
Traffic Load ◽  
Transport Networks ◽  
Traffic Conditions ◽  
Probe Vehicle ◽  
Vehicle Data ◽  
Network Operations ◽  
Network States ◽  
The Impact ◽  
Proper Operation

Transport networks are essential for societies. Their proper operation has to be preserved to face any perturbation or disruption. It is therefore of paramount importance that the modeling and quantification of the resilience of such networks are addressed to ensure an acceptable level of service even in the presence of disruptions. The paper aims at characterizing network resilience through weighted degree centrality. To do so, a real dataset issued from probe vehicle data is used to weight the graph by the traffic load. In particular, a set of disrupted situations retrieved from the study dataset is analyzed to quantify the impact on network operations. Results demonstrate the ability of the proposed metrics to capture traffic dynamics as well as their utility for quantifying the resilience of the network. The proposed methodology combines different metrics from the complex networks theory (i.e., heterogeneity, density, and symmetry) computed on temporal and weighted graphs. Time-varying traffic conditions and disruptions are analyzed by providing relevant insights on the network states via three-dimensional maps.

The Multi-Relationship Evaluation Design Framework: Designing Testing Plans to Comprehensively Assess Advanced and Intelligent Technologies

2010 ◽  
Author(s):  
Brian A. Weiss ◽  
Linda C. Schmidt ◽  
Harry A. Scott ◽  
Craig I. Schlenoff
Keyword(s):  
Intelligent Systems ◽  
New Technologies ◽  
Evaluation Framework ◽  
Evaluation Design ◽  
Design Elements ◽  
Summative Assessments ◽  
Extensive Evaluation ◽  
Level Of Knowledge ◽  
Definition Of ◽  
Key Terms

As new technologies develop and mature, it becomes critical to provide both formative and summative assessments on their performance. Performance assessment events range in form from a few simple tests of key elements of the technology to highly complex and extensive evaluation exercises targeting specific levels and capabilities of the system under scrutiny. Typically the more advanced the system, the more often performance evaluations are warranted, and the more complex the evaluation planning becomes. Numerous evaluation frameworks have been developed to generate evaluation designs intent on characterizing the performance of intelligent systems. Many of these frameworks enable the design of extensive evaluations, but each has its own focused objectives within an inherent set of known boundaries. This paper introduces the Multi-Relationship Evaluation Design (MRED) framework whose ultimate goal is to automatically generate an evaluation design based upon multiple inputs. The MRED framework takes input goal data and outputs an evaluation blueprint complete with specific evaluation elements including level of technology to be tested, metric type, user type, and, evaluation environment. Some of MRED’s unique features are that it characterizes these relationships and manages their uncertainties along with those associated with evaluation input. The authors will introduce MRED by first presenting relationships between four main evaluation design elements. These evaluation elements are defined and the relationships between them are established including the connections between evaluation personnel (not just the users), their level of knowledge, and decision-making authority. This will be further supported through the definition of key terms. An example will be presented in which these terms and relationships are applied to the evaluation design of an automobile technology. An initial validation step follows where MRED is applied to the speech translation technology whose evaluation design was inspired by the successful use of a pre-existing evaluation framework. It is important to note that MRED is still in its early stages of development where this paper presents numerous MRED outputs. Future publications will present the remaining outputs, the uncertain inputs, and MRED’s implementation steps that produce the detailed evaluation blueprints.

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