scholarly journals Operating Speed Prediction Models for Tangent Segments: A Brief Review

2021 ◽  
Vol 7 (12) ◽  
pp. 2150-2164
Author(s):  
Musab AbuAddous

This paper provides a review of studies aimed at developing operating speed prediction models for road tangent sections. The review included many studies, conducted in different geographical areas of the world, in terms of road classification, types of vehicles, techniques and devices used in data collection, number of study sites, the principle adopted in extracting the free-flow speed, as well as the topography that the road path passes through and grads of the studied sections. Moreover, this review mentioned the analysis methods adopted in the modeling, and included the model formulas that the researchers have reached in their studies, as it showed all the geometric elements and traffic characteristics that appeared in the models as independent variables. The author has avoided critiquing or evaluating the methodologies of the reviewed research and accordingly this paper has been prepared for documentation only. The author aims primarily to save the effort and time of graduate students and researchers interested in modeling the operating speed on straight segments, as all data and information are arranged in tables and coordinated for this purpose. Doi: 10.28991/cej-2021-03091784 Full Text: PDF

2021 ◽  
Vol 17 ◽  
pp. 595-603
Author(s):  
Panagiotis Lemonakis ◽  
George Botzoris ◽  
Athanasios Galanis ◽  
Nikolaos Eliou

The development of operating speed models has been the subject of numerous research studies in the past. Most of them present models that aim to predict free-flow speed in conjunction with the road geometry at the curved road sections considering various geometric parameters e.g., radius, length, preceding tangent, deflection angle. The developed models seldomly take into account the operating speed profiles of motorcycle riders and hence no significant efforts have been put so far to associate the geometric characteristics of a road segment with the speed behavior of motorcycle riders. The dominance of 4-wheel vehicles on the road network led the researchers to focus explicitly on the development of speed prediction models for passenger cars, vans, pickups, and trucks. However, although the motorcycle fleet represents only a small proportion of the total traffic volume motorcycle riders are over-represented in traffic accidents especially those that occur on horizontal curves. Since operating speed has been thoroughly documented as the most significant precipitating factor of vehicular accidents, the study of motorcycle rider's speed behavior approaching horizontal curves is of paramount importance. The subject of the present paper is the development of speed prediction models for motorcycle riders traveling on two-lane rural roads. The model was the result of the execution of field measurements under naturalistic conditions with the use of an instrumented motorcycle conducted by experienced motorcycle riders under different lighting conditions. The implemented methodology to determine the most efficient model evaluates a series of road geometry parameters through a comprehensive literature review excluding those with an insignificant impact to the magnitude of the operating speeds in order to establish simple and handy models.


Author(s):  
Haneen Farah ◽  
Aries van Beinum ◽  
Winnie Daamen

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.


Author(s):  
Avi Thiessen ◽  
Karim El-Basyouny ◽  
Suliman Gargoum

Information about operating speeds is essential to design better roads, model traffic emissions, and ensure design consistency while efficient and safe operations on roads are maintained. Therefore, understanding how different factors affect operating speeds and developing operating speed prediction models are critical research issues. Many studies have developed such models on rural roads and highways, but only a few studies have considered development of such models on urban roads and fewer still on tangential segments. This present study attempted to address these limitations by developing operating speed models with data from 249 tangential road segments in the city of Edmonton, Alberta, Canada. A generalized linear model was developed with panel data, and the primary aim was to explore the relationships between operating speeds on urban roads and features of the road environment. To study the impact of road elements on different road types, three models were created: one that combined arterial and collector locations, one for arterials only, and one for collector roads only. The results revealed that roads with sidewalks that were farther away from the road and with low object density or tree density were all associated with higher operating speeds. Locations with monolithic walks on both sides of the road had lower operating speeds. Furthermore, operating speeds decreased as access increased, while longer roads had higher operating speeds. One major takeaway was that the elements differed between road classes. The two variables, which stood out in that respect, were medians and bus stops.


2005 ◽  
Vol 32 (2) ◽  
pp. 388-399 ◽  
Author(s):  
Laurel Richl ◽  
Tarek Sayed

The most frequently used criteria to evaluate design consistency are the difference between design speed and operating speed, operating speeds on successive elements, and assumed side friction of the road and that demanded by the driver. The operating speed, often obtained using speed prediction models, influences each design consistency criteria. There has been considerable research in developing design consistency measures and evaluation tools, but little research has been done on the influence that different speed prediction models have on design consistency criteria. In addition, there has been little research as to how design factors such as driver perception of combined horizontal and vertical curves influence speed prediction models. This paper investigates how the selection of speed prediction models and driver perception of combined horizontal and vertical curves influence design consistency evaluation. The selection of the speed prediction model has a significant impact on design consistency evaluation. The use of perceived radius, which accounts for driver perception of combined alignments, slightly influenced the outcome of the design consistency evaluation.Key words: design consistency, speed prediction models, driver perception, combined horizontal and vertical curves, perceived radius, geometric design.


ICSDC 2011 ◽  
2012 ◽  
Author(s):  
Tommaso Esposito ◽  
Raffaele Mauro ◽  
Francesca Russo ◽  
Gianluca Dell'Acqua

2008 ◽  
Vol 35 (5) ◽  
pp. 443-453 ◽  
Author(s):  
Rizwan A. Memon ◽  
G. B. Khaskheli ◽  
A. Sami Qureshi

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.


2018 ◽  
Vol 12 (2) ◽  
pp. 130-137
Author(s):  
Avijit Maji ◽  
Dharamveer Singh ◽  
Naman Agrawal ◽  
Musharraf Zaman

2000 ◽  
Vol 1701 (1) ◽  
pp. 95-103 ◽  
Author(s):  
Joseph P. Tarris ◽  
John M. Mason ◽  
Nicholas D. Antonucci

A research effort is progressing to develop a rational process for designing roadway geometric elements on low-speed urban streets and using a “target”operating speed as the preselected design speed. The goal is to provide geometric street designs that reflect the in situ operating environment (form to follow function). Such an approach produces geometric conditions that result in operating speeds that are consistent with driver expectations and commensurate with the function and purpose of the roadway. The data collection methodology being used to develop a speed-prediction model between operating speed and roadway geometry, roadside features, land use, and traffic engineering considerations is also described. A comparison of design speed and operating speed for one study site is provided as an example of anticipated results.


Author(s):  
Jaydip Goyani ◽  
Purvang Chaudhari ◽  
Shriniwas Arkatkar ◽  
Gaurang Joshi ◽  
Said M. Easa

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