Development of models for predicting speed on horizontal curves for two-lane rural highways

Joint Authors

Abd al-Mawjud, Ayman A.
Sofia, Gandhi G.

Source

The Arabian Journal for Science and Engineering. Section B, Engineering

Issue

Vol. 33, Issue 2B (31 Oct. 2008), pp.365-377, 13 p.

Publisher

King Fahd University of Petroleum and Minerals

Publication Date

2008-10-31

Country of Publication

Saudi Arabia

No. of Pages

13

Main Subjects

Civil Engineering

Topics

Abstract AR

تعتبر الأقواس الأفقية من أهم العوامل التي تؤثر في سرعة المركبات في الطرق ذات المسربين.

و تهدف هذه الدراسة إلى إيجاد معادلات تنبؤية لسرعة المركبات في مناطق الأقواس.

و قد تم جمع المعلومات المرورية من 28 موقعا في شمال العراق، تم تدقيق المعادلات التنبؤية الأربع التي تم إيجادها باستخدام معلومات مرورية إضافية تم جمعها من 20 موقعا آخر.

و قد قمنا بقياس السرعة لأكثر من 7000 مركبة صغيرة، حيث تم إيجاد مجموعة من معادلات الانحدار، تبين أن المتغيرين الرئيسين غير المعتمدين كانا نصف قطر القوس و سرعة المركبات عند الاقتراب.

و قد أعطت معادلات السرعة التنبؤية معدل نسبة الخطأ المطلق بين 9.1-7%، بينما كان معدل نسبة الخطأ المطلق الكلي 8.03%.

و قد تم توضيح مجال الخطأ بين المعادلات التنبؤية و المقاييس الحقلية باستخدام الرسم الصندوقي.

Abstract EN

A variety of physical factors may influence speeds on two-lane highways.

Horizontal curvature has the greatest impact on speed.

The objective of this study was to develop curve–speed prediction equations using data collected at 28 sites in northern Iraq.

Four equations that include the effect of curve radius and grade on the predicted 85th percentile curve speed were developed and subsequently validated using observed values from another 20 sites.

The speed of more than 7000 passenger cars was measured during the study.

A series of regression models were developed.

The main independent variables chosen for use in the regression analyses were radius of the curve and approach speed.

The speed prediction equations performed well, in that the mean absolute percent error ranged between 7 and 9 percent and there was an overall mean absolute percent error of 8 percent.

Box plots were developed to demonstrate graphically the range of error between the predicted speeds and the field measurements.

American Psychological Association (APA)

Abd al-Mawjud, Ayman A.& Sofia, Gandhi G.. 2008. Development of models for predicting speed on horizontal curves for two-lane rural highways. The Arabian Journal for Science and Engineering. Section B, Engineering،Vol. 33, no. 2B, pp.365-377.
https://search.emarefa.net/detail/BIM-330161

Modern Language Association (MLA)

Abd al-Mawjud, Ayman A.& Sofia, Gandhi G.. Development of models for predicting speed on horizontal curves for two-lane rural highways. The Arabian Journal for Science and Engineering. Section B, Engineering Vol. 33, no. B2 (Oct. 2008), pp.365-377.
https://search.emarefa.net/detail/BIM-330161

American Medical Association (AMA)

Abd al-Mawjud, Ayman A.& Sofia, Gandhi G.. Development of models for predicting speed on horizontal curves for two-lane rural highways. The Arabian Journal for Science and Engineering. Section B, Engineering. 2008. Vol. 33, no. 2B, pp.365-377.
https://search.emarefa.net/detail/BIM-330161

Data Type

Journal Articles

Language

English

Notes

Includes bibliographical references : p. 376-377

Record ID

BIM-330161