Assessing Major Safety Issues on Highway-Railroad Grade Crossings along the Addis Ababa Light Rail Transit

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Date

2016-08

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Publisher

Addis Ababa University

Abstract

Of the whole railway line, the major part where frequent accidents occur is highwayrailroad at grade crossings. The grade crossings along Addis Ababa Light Rail Transit (AA LRT) are located at areas with high pedestrian and vehicular traffic. Therefore safety levels at AALRT grade crossings will be major concern during operation. This research study assessed major safety issue at highway-railroad at grade crossings along AA LRT using accident rating models and highway-railroad level crossing engineering design guidelines and standards. The study identified the design and construction of highway-railroad level crossings along AALRT satisfied most of the design guidelines and criteria outlined by American Railway Engineering and Maintenance-Of-Way Association AREMA manual, Chinese standard GB50090, Federal Highway Association FHWA handbook and manual on uniform traffic control devices MUTCDS. Despite being compliant to the above design standards, level crossings at Tsehay Realestate roundabout, Salitemihiret roundabout, Adey Ababa and Sebategna junction found to have highest accident number. The geometry of the crossings and the traffic volume operating at these sections of AALRT are found to be major reasons for such high accident rate. For type ‘F’ traffic control system the smallest expected accident number per year is 0.28 at Kality side Meshualekiya roundabout level crossing. This result is higher than 0.075 a threshold value for the use of type ‘G’ traffic control system. Therefore the gates at the level crossings of AALRT should start operation. When gates are operational, accident frequencies from US DOT model are greater than 0.2 on the above hazardous level crossings. This 0.2 accident/year is the threshold value for grade separation. Therefore level crossings at Tsehay Realestate roundabout, Salitemihiret roundabout, Adey Ababa and Sebategna junction should be considered for grade separation if the cost of grade separation can be economically justified based on fully allocated life-cycle costs.

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Keywords

Highway-railroad grade crossing safety, Light rail transit system, design standards, accident rating models

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