State of the Art of Highway Geometric Design Consistency

Gibreel, G. M.; Easa, Said M.; Hassan, Yasser; El-Dimeery, I. A.

doi:10.1061/(asce)0733-947x(1999)125:4(305)

Cited by 149 publications

(55 citation statements)

References 7 publications

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“…Driver workload is defined as the time rate at which drivers must perform a given amount of driving tasks that increases with the increase of the complexity in highway geometric features (Gibreel et al, 1999). Driver workload may be a more appealing approach for identifying inconsistencies than operating speed because it represents the effort that the roadway requires from drivers, while operating speed is only one of the observable outputs of the driving task (Ng and Sayed, 2004).…”

Section: Introductionmentioning

confidence: 99%

“…The most commonly used criteria to evaluate highway design consistency are based on operating speed evaluation (Gibreel et al, 1999), often defined as the 85 th percentile speed ( ) of a sample of vehicles, and obtained by using operating speed prediction models. This specific measure of speed can be used in consistency evaluation by examining disparities between design speed ( ) and or examining the differences in between successive elements of the road ( ).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

New geometric design consistency model based on operating speed profiles for road safety evaluation

Torregrosa¹,

Pérez-Zuriaga²,

Campoy-Ungría³

et al. 2013

Accident Analysis & Prevention

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ElsevierCamacho Torregrosa, FJ.; Pérez Zuriaga, AM.; Campoy Ungria, JM.; García García, A. (2013). New geometric design consistency model based on operating speed profiles for road safety evaluation. Accident Analysis and Prevention. 61:33-42. doi:10.1016/j.aap.2012.10.001. 1 NEW GEOMETRIC DESIGN CONSISTENCY MODEL BASED ON OPERATING SPEED PROFILES FOR ROAD SAFETY EVALUATION ABSTRACTIn order to reduce road fatalities as maximum as possible, this paper presents a new methodology to evaluate road safety in both design and redesign stages of two-lane rural highways. This methodology is based on the evaluation of road geometric design consistency, determining one value which will be a surrogate measure of the safety level of a two-lane rural road segment. The consistency model presented in this paper is based on the consideration of continuous operating speed profiles. The models used for their construction have been obtained by using an innovative GPS-data collecting method, based on continuous operating speed profiles recorded from individual drivers. This new methodology allowed the researchers to observe the actual behavior of drivers and to develop more accurate operating speed models than those which are based on spot-speed data collection. That means a more accurate approximation to the real phenomenon, and thus a better consistency measurement. Operating speed profiles were built for 33 Spanish two-lane rural road segments, and several consistency measurements based on the global and local operating speed were checked. The final consistency model takes into account not only the global dispersion of the operating speed, but also some indexes that consider both local speed decelerations and speeds over posted speeds. For the development of the consistency model, the crash frequency for all sites was considered, obtaining a model directly related to safety. This allows estimating the number of crashes of a road segment by means of the calculation of its geometric design consistency. Consequently, the present consistency evaluation method becomes an innovative tool that can be used as a surrogate measure to estimate road safety of a road segment even before its construction.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

New geometric design consistency model based on operating speed profiles for road safety evaluation

Torregrosa¹,

Pérez-Zuriaga²,

Campoy-Ungría³

et al. 2013

Accident Analysis & Prevention

View full text Add to dashboard Cite

show abstract

“…Models developed in North America (Lamm & Choueiri [5], Moral & Tallarico [6], Gibreel et al [7], Krammes [8], Fitzpatrick et al [9], Figueroa, Medina, and Tarko [10] Misachi & Hassan [11]) deal with operating speeds on individual elements.…”

Section: Estimation Of Free Flow Speed On Two-lane Highways Is a Greamentioning

confidence: 99%

Modelling Free Flow Speed on Two-Lane Rural Highways in Bosnia and Herzegovina

Lovrić

Cvitanić

Breški

2014

PROMET

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“…Those efforts have resulted in a wide array of tools for speed modeling (Fitzpatrick et al 2000a;TRB 2011) and design consistency evaluation (Krammes et al 1995;Gibreel et al 1999;Fitzpatrick et al 2000b) that are used by practitioners worldwide. Several issues arise from the complexity of studying driving speeds, however, and questions about the most relevant speed determinants and measures are frequently debated among researchers.…”

Section: Introductionmentioning

confidence: 99%

Flexible Stochastic Frontier Approach to Predict Spot Speed in Two-Lane Highways

2016

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The approach to spot speed prediction in two-lane highways followed in this study aims to evaluate the effects of a comprehensive set of speed factors, with a special focus on the geometric characteristics of the road segment to which the element belongs. Two flexible models were developed for different types of roads based on a stochastic frontier formulation in which the maximum operating speed is estimated as a function of road geometrics and the one-sided disturbance accounts for diversity in driving behavior and vehicle characteristics, allowing the estimation of any percentile speed. The models are applicable to horizontal curves and tangents and consider both on-site characteristics and aggregated variables characterizing the road segment. The results show a clear influence of segment features on different percentile spot speeds, revealing that recent driving experience and expectations about the quality of the geometric design influence the way a driver approaches a specific road element. Additionally, this study contributes to addressing some of the limitations of existing speed models identified in 2 the literature.

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State of the Art of Highway Geometric Design Consistency

Cited by 149 publications

References 7 publications

New geometric design consistency model based on operating speed profiles for road safety evaluation

New geometric design consistency model based on operating speed profiles for road safety evaluation

Modelling Free Flow Speed on Two-Lane Rural Highways in Bosnia and Herzegovina

Flexible Stochastic Frontier Approach to Predict Spot Speed in Two-Lane Highways

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