Papers by Basil Psarianos
GR Road Congress 2011, 2011
ABSTRACT The aim of this study is to present the results of a scientific research concerning the ... more ABSTRACT The aim of this study is to present the results of a scientific research concerning the real curvature of vehicle trajectory compared with the design curvature for rural single carriageway (two lane highway). To address this problem, a series of video measurements on vehicles were conducted at four curves selected so as to satisfy specific geometric restrictions and a wide range of curvature (from 950.76 gon/km to 67.65 gon/km). The rate of curvature was estimated via photogrammetric techniques. It was proved that the necessary number of free flow vehicles for this research was over a hundred per curve. It was also indirectly estimated the speed of each vehicle as well as the operating speed associated with each curve. Moreover, it was tested if there is any correlation between the operating speed and the real mean rate of curvature of vehicles’ trajectory and between the operating speed and the design curvature. It was also estimated the design speed of each curve according to the American (AASHTO) and Greek Guidelines. Furthermore, it was investigated if there is any correlation between the mean of real rate of curvature of vehicles’ path and the design rate of curvature. Finally, it was tested if the side friction factor demand for the vehicles of each curve exceeds the available lateral friction factor according to American, German and Greek Guidelines. Ultimately, many efforts have been done worldwide by many investigators implementing a variety of ways so as the real rate of curvature and the frequency of accidents to be safely correlated. This is a serious problem and this study contributes to this effort to a certain extent.
The articles included in this circular were presented as part of a workshop during the 84th Annua... more The articles included in this circular were presented as part of a workshop during the 84th Annual Meeting of the Transportation Research Board and include work in Germany and the United Kingdom. Two of the articles deal with street design in small towns while another presents context-sensitive design aspects of arterial streets within big cities (in this case Berlin, Germany). The fourth article addresses issues relative to historic sites (in this case Stonehenge, U.K.). The workshop also included a roundtable discussion where participants exchanged ideas and experiences on similar projects and issues. Highlights from this discussion are included in this introduction.
Foreword his report is a synthesis of existing operating speed models developed in different regi... more Foreword his report is a synthesis of existing operating speed models developed in different regions of the world. The models are grouped according to roadway type. Limitations and deficiencies in existing operating speed models and suggestions for future work are also identified. Practitioner perspectives on the potential use of speed prediction models in road design practice are provided from both the perspective of the United States and the international community. The document was prepared by members and friends of the Transportation Research Board's Operational Effects of Geometrics Committee (AHB65).
Transportation research procedia, 2023
Transportation research procedia, 2023
Transportation research circular, Oct 1, 2016
Transportation research circular, Jul 1, 2011
The objectives of the report are to identify and document existing operating speed models develop... more The objectives of the report are to identify and document existing operating speed models developed in different regions of the world. The models are grouped according to roadway type. In addition, authors of the report identify several limitations and deficiencies in the existing ...
Journal of Transportation Engineering, Part A: Systems, 2021
AbstractThe objective of this paper is the creation of a suitable methodology capable of deployin... more AbstractThe objective of this paper is the creation of a suitable methodology capable of deploying elements that characterize the existing infrastructure on rural two-lane highways regarding the lo...
Advances in transportation studies, 2018
Advances in transportation studies, 2018
Non-geodetic activities practised around the globe are not adequately known to the surveying soci... more Non-geodetic activities practised around the globe are not adequately known to the surveying society. However such knowledge will help the profession overcome its current problems and redefinition of the surveyor will ensure his survival in an era of globalisation. In this paper therefore a brief description is given of the main existing non-geodetic activities associated with a surveying title, with their educational requirements and countries in which they are practised, and which are either not represented or under-represented in FIG.
Optimal highway alignment design has been a topic widely investigated for over four decades. Howe... more Optimal highway alignment design has been a topic widely investigated for over four decades. However, the design of highways largely remains an interactive, experience-based process. Indeed, existing work on alignment optimization mostly focuses on feasibility study oriented, corridor level designs. This paper proposes a sequential optimization model for designing highway alignments at the preliminary design level. For that purpose, unlike past work, the model takes into account detailed design variables, parameters and constraints. A highway alignment design model, coupled with a metaheuristic search method are exploited and applied for designing a highway alignment to a sample terrain. Results indicate that the optimized alignment yields an over 35% improvement in earthwork costs compared to a base case of a non-optimized counterpart.
This research aims to enrich the limited literature on the impact of day of time/lighting conditi... more This research aims to enrich the limited literature on the impact of day of time/lighting conditions on operating speeds. The quantification of the operating speed changes follows the guidelines of the international literature. An intensive and carefully designed data collection procedure was followed by exploratory and confirmatory statistical analyses, which resulted in speed prediction models for rural two-lane roads. A large number of speed data (5440 observations) were collected by the use of radar-guns, operated by a trained engineer, from 29 curves and 5 straight segments in two-lane rural roads in Cyprus, both during the day and at night. Operating speeds were calculated for all segments, and were analyzed according to various characteristics, such as time of day, and lane width. A number of speed-prediction models were also specified and estimated, and their goodness of fit was evaluated. The results were compared with other similar studies that have been recently performed...
Current Trends in Civil & Structural Engineering, 2019
Transportation Research Record: Journal of the Transportation Research Board, 2019
Skew superelevation has proven to be an efficient pavement constructional measure to address hydr... more Skew superelevation has proven to be an efficient pavement constructional measure to address hydroplaning phenomena under specific critical superelevation runoff designs. However, this technique has raised concerns about user’s comfort when driving over the skewed edge of the pavement, especially for heavy vehicles and when the traveling speed is higher than the design speed. This paper aims to evaluate the driving comfort outcome on an improved skew superelevation design, where a rounding of the skew edge has been applied. This is achieved through the use of a simulation program which examines the vehicle and driver behavior when passing over it. The simulation program estimates many parameters including the lateral and vertical accelerations ( Gy and Gz) imposed on both elements, the vehicle and the driver. This evaluation is made for different alignment designs provided in the freeway design and for a broad range of especially high velocities ranging from 80 to 160 km/h (50–100 m...
Transportation Research Record: Journal of the Transportation Research Board, 2017
Hydroplaning and the corresponding hydroplaning speed of a vehicle are critical road safety conce... more Hydroplaning and the corresponding hydroplaning speed of a vehicle are critical road safety concerns. To avoid hydroplaning, nine technical measures are available. One of the most effective is the construction of skew superelevation runoff at the critical pavement section of a highway, especially in highway rehabilitation and reconstruction projects. The concept was introduced in the German RAS-L design guide of 1984; its implementation is found mainly in central European countries. Skew superelevation runoff was adopted in recent freeway projects, some of which are reconstructions of existing two-lane highways into freeways to address identified sections with high potential for hydroplaning. Its use under normal traffic has resulted in concerns about its safety and comfort effectiveness. To investigate the operational and safety performance of the constructed skew superelevation runoffs, accurate triaxial acceleration measurements were carried out on the Korinthos-Patra freeway in ...
European Transport Research Review, 2016
Introduction Stopping Sight Distance control of passing lanes of divided highways represents curr... more Introduction Stopping Sight Distance control of passing lanes of divided highways represents currently a discussion point among researchers. A 3-D approach to address the issue is accepted as the overall solution to the problem by both researchers and contemporary design policies. This paper aims to contribute to the problem by presenting a sound and practical design solution to it with an analytic and a design values based format. Methods The solution approach consists of both a realistic description of the 3-D highway configuration and a 3-D vehicle kinematics calculation of the stopping maneuver along the vehicle's actual path. A SSD control method, previously developed by the authors', that relates concurrently the 3D configuration of a roadway to the kinematics of a vehicle moving along the actual roadway path, is applied, as a tool for the assessment of critical design parameters directly related to SSD adequacy. Results A rather comfortable alignment case consisting of a left curved divided highway overlapped with crest vertical curve parameters for numerous horizontal-vertical arrangements is examined, where an extensive area of SSD inadequacy during emergency braking procedure is reported. Conclusions The authors propose that the optimal solution to achieve SSD adequacy on left curved divided highways is to increase object height. This would preserve design consistency as well as driver expectations, by avoiding the need for lateral widening or site-specific speed limits. More specifically the object height is suggested to be equivalent to the driver's height of 1.08 m (AASHTO 2011). This would require additional stop lights on those vehicles whose stop lights are currently below this level. Although such a requirement regarding the current vehicle fleet is not feasible, vehicle industries as well as road design guidelines should address this issue in the near future.
The adopted 2-D Stopping Sight Distance (SSD) adequacy investigation in current design practice m... more The adopted 2-D Stopping Sight Distance (SSD) adequacy investigation in current design practice may lead to design deficiencies due to inaccurate calculation of the available sight distance. Although this concern has been identified by many research studies in the past, none of those suggested a comprehensive methodology to simulate from a 3-D perspective concurrently both the cross-section design and the vehicle dynamics in space during emergency braking conditions. The proposed methodology can accurately perform SSD adequacy investigation in any 3-D road environment where the ground, road and roadside elements are inserted by identifying areas of interrupted vision lines between driverobstacle being less than the required distance necessary to bring the vehicle to a stop condition. The precision of the available SSD definition is a function of the selected incremental distance (calculation step) between two sequential points. The present approach provides flexibility among every road design and/or vehicle dynamic parameter inserted (e.g. lateral positioning and height of both driver and obstacle, vehicle speed and braking friction variations), as well as direct overview regarding design elements that restrict the driver's vision and create SSD inadequacies. As a result, precious guidance is provided to the designer for further alignment improvement but mostly an accurate aid to implement geometric design control criteria with respect to both existing as well as new road sections is delivered. The efficiency of the proposed methodology is demonstrated on a specific case study. The used software herein is part of "H12" road design software, developed at the National Technical University of Athens (NTUA).
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Papers by Basil Psarianos
This paper aims to evaluate the driving comfort outcome on an improved skew superelevation design, where a rounding of the skew edge has been applied. This is achieved through the use of a simulation program which examines the vehicle and driver behavior when passing over it. The simulation program estimates many parameters including the lateral and vertical accelerations (Gy and Gz) imposed on both elements, the vehicle and the driver. This evaluation is made for different alignment designs provided in the freeway design and for a broad range of especially high velocities ranging from 80 to 160 kph (50-100 mph), as well as for different types of heavy vehicles. Also the influence to the above parameters has been investigated in respect with the distance between two consecutive skew superelevations, concerning cases of entering and exiting a simple low length curve.
The outcomes are classified in order to evaluate their variability as affected by each parameter change (speed, geometry, vehicle). Simulation results are compared with thresholds, as provided in the international literature, to ensure driver comfort and high level of road safety.