Safety performance of freeway sections and relation to length of speed-change lanes

Sarhan, Mohamed; Hassan, Yasser; Halim, A O Abd El

doi:10.1139/l07-135

Cited by 43 publications

(38 citation statements)

References 4 publications

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“…Zeng [18] used the accident assessment method to analyze the collision rate on the interchange through accident data from a freeway in Florida for three years. Sarhan [19] used regression analysis to study the relationship between geometric parameters and traffic flow characteristics of 26 interchanges, and used the accident data to establish a negative binomial distribution model to analyze the relationship between geometric parameters of road and traffic flow and traffic accidents. Kita [20] analyzed the critical clearance selection of vehicles in the merging area of interchange, and the results show that the length of acceleration lane has a certain influence on the driver's choice of confluence gap.…”

Section: Literature Reviewmentioning

confidence: 99%

Driving behavior and safety analysis at OSMS section for merged, one-way freeway based on simulated driving safety analysis of driving behaviour

Lyu

Cao

et al. 2020

PLoS ONE

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In order to study driving performance at the opening section of median strip (hereafter OSMS) on the freeway capacity expansion project, this study separately controlled 9 different simulated experimental scenarios of OSMS length and freeway traffic flow. 25 participants were recruited to perform 225 simulated driving tests using the driving simulator, and the analysis of variance (ANOVA) was used to analyze the driving characteristics which can represent the safety context. The results show that the safety parameters of driving are different when the length of OSMS and the traffic flow are different. When the traffic flow is low or moderate, the OSMS length can significantly affect the speed of the vehicle and the maximum values of time to collision. The higher the traffic flow, the smaller the minimum values of time headway. As the length of the OSMS decreases, the vehicles are more generally concentrated at the end of the opening area with the minimum values of time headway. The study also found that when the traffic volume is high, the impact of the OSMS length on driving performance will be weakened. In addition, the OSMS length and the traffic flow have little impact on driving comfort. Additionally, when the traffic flow is low or moderate, the opening length can significantly affect the driving behavior and safety of the vehicle. However, when the traffic volume is high, the impact of the opening length on them will be relatively weakened to some extent. Therefore, it is advised that in the case of freeways with large traffic volume, merely extending the length of the opening section does not necessarily optimize safety. Rather, the actual traffic density of the road should be carefully considered before a design length is adopted.

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Section: Literature Reviewmentioning

confidence: 99%

Driving behavior and safety analysis at OSMS section for merged, one-way freeway based on simulated driving safety analysis of driving behaviour

Lyu

Cao

et al. 2020

PLoS ONE

View full text Add to dashboard Cite

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“…The wide variety of site geometric conditions, traffic volumes, ramp types, and design layouts could increase or decrease operation levels. [10][11][12][13] Cassidy et al…”

Section: Literature Reviewmentioning

confidence: 99%

Selection for optimal exit ramp type on Florida’s freeways based on operational analysis

Wang

Lü

et al. 2016

Advances in Mechanical Engineering

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In the State of Florida, several types of exit ramps are used, including single-lane exit ramp with a taper, single-lane exit ramp without a taper, two-lane exit ramp with an optional lane, and two-lane exit ramp without an optional lane. Drivers exiting freeways need to make maneuver decisions (lane change, lane merge, and decelerate) prior to exit ramps in order to access cross roads at interchanges. Different exit ramp types lead to varying driving maneuvers when exiting, affecting the operational and safety performance on freeways. Based on the facts, there are several issues that need to be addressed in selecting the most optimum types of freeway exit ramps. This article mainly focuses on the comparison of operational performances of different ramp types and tries to present a method for choosing the optimal one. A data collection of 24 sites in Florida were conducted, and traffic simulations by Traffic Software Integrated System: Corridor Simulation were employed. Mathematical models were built to evaluate impacts of these ramps based on simulations. And an analytical hierarchy process method was applied to assign significance weight for all selected measures of effectiveness in terms of Florida questionnaire. Finally, an aggregate numerical evaluation was provided according to calculated data.

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“…ese two categories include the real-accident data analyzing and the simulation-based safety study. In the real-accident studies, the effect of some factors (such as mainline speed at the beginning of the weaving segments, the speed difference between the beginning and the end of the weaving segment, the logarithm of the volume, the maximum length of the weaving area [1], the heavy vehicle rate, the hourly traffic volume, the speed differential between cars and heavy vehicles, the number of accesses [2], the number of vehicles that enter and exit the freeway at a specific segment, the length of the speed change lane, the speed of off-ramps [3], parallel-type or taper-type exit ramps [4], left-side or right-side merging and diverging areas [5,6], the number of lanes on freeways, the number of lanes on ramps, and the speeding-related crashes [7]) on the number and/or severity of accidents was separately investigated and some models were developed. When there are no registered data about the accidents in a specific facility or when someone is trying to design that facility or when the facility has not yet been built, simulation-based safety studies/estimations such as conflict analysis by microscopic simulation and surrogate safety measures (SSMs) including time-to-collision (TTC), postencroachment time (PET), proportion of stopping distance (PSD), crash potential index (CPI), unsafe density (UD), max speed (Max S), relative speed (ΔV), kinetic energy (KE), and deceleration rate to avoid collision (DRAC) are often used to estimate the danger or risk of possible collisions.…”

Section: Introductionmentioning

confidence: 99%

Proposing New Methods to Estimate the Safety Level in Different Parts of Freeway Interchanges

Behbahani

Hosseini

Taherkhani

et al. 2018

Advances in Civil Engineering

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Since attention to the safety of traffic facilities including freeway interchanges has been increased during recent years, accident prediction models are being developed. Simulation-based surrogate safety measures (SSMs) have been used in the absence of real collision data. But, obtaining different outputs from different SSMs as safety indicators had led to a complexity of using them as the collision avoidance system basis. Additionally, applying SSM requires trajectory data which can be hardly obtained from video processing or calibrated microsimulations. Estimating safety level in different parts of freeway interchanges through a new proposed method was considered in this paper. Fuzzy logic was applied to combine the outputs of different SSMs, and an index called no-collision potential index (NCPI) was defined. 13608 calibrated simulations were conducted on different ramps, weaving, merge, and diverge areas with different geometrical and traffic characteristics, and NCPI was determined for every case. The geometrical and traffic characteristics formed input data of two safety estimator models developed by Artificial Neural Network and Particle Swarm Optimization. Ten freeway interchanges were investigated to calibrate the simulations and to ensure the validity of the fuzzy method and accuracy of the models. Results showed an appropriate and accurate development of the models.

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Safety performance of freeway sections and relation to length of speed-change lanes

Cited by 43 publications

References 4 publications

Driving behavior and safety analysis at OSMS section for merged, one-way freeway based on simulated driving safety analysis of driving behaviour

Driving behavior and safety analysis at OSMS section for merged, one-way freeway based on simulated driving safety analysis of driving behaviour

Selection for optimal exit ramp type on Florida’s freeways based on operational analysis

Proposing New Methods to Estimate the Safety Level in Different Parts of Freeway Interchanges

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