Getu Segni Tulu

Investigation of pedestrian crashes on two-way two-lane rural roads in Ethiopia.

Understanding pedestrian crash causes and contributing factors in developing countries is critically important as they account for about 55% of all traffic crashes. Not surprisingly, considerable attention in the literature has been paid to road traffic crash prediction models and methodologies in developing countries of late. Despite this interest, there are significant challenges confronting safety managers in developing countries. For example, in spite of the prominence of pedestrian crashes occurring on two-way two-lane rural roads, it has proven difficult to develop pedestrian crash prediction models due to a lack of both traffic and pedestrian exposure data. This general lack of available data has further hampered identification of pedestrian crash causes and subsequent estimation of pedestrian safety performance functions. The challenges are similar across developing nations, where little is known about the relationship between pedestrian crashes, traffic flow, and road environment variables on rural two-way roads, and where unique predictor variables may be needed to capture the unique crash risk circumstances. This paper describes pedestrian crash safety performance functions for two-way two-lane rural roads in Ethiopia as a function of traffic flow, pedestrian flows, and road geometry characteristics. In particular, random parameter negative binomial model was used to investigate pedestrian crashes. The models and their interpretations make important contributions to road crash analysis and prevention in developing countries. They also assist in the identification of the contributing factors to pedestrian crashes, with the intent to identify potential design and operational improvements.

Injury severity of pedestrians involved in road traffic crashes in Addis Ababa, Ethiopia

ABSTRACT Addis Ababa, with a population of four million, is the largest urban center in Ethiopia. Recently, road traffic crashes, and particularly pedestrian crashes, have become a challenging problem within the city. Walking is the principal mode of transportation in Addis Ababa, accounting for about 60% of daily trips, whereas pedestrian injuries account for about 85% of total injury crashes. Noting this disparity, the objective of this study was to examine the influence of roadway geometric, traffic features, spatial characteristics, and driver/pedestrian demographics on injury severities of pedestrians in Addis Ababa. Police reported pedestrian crashes in Addis Ababa from 2009 to 2012 have been modelled using a random-parameters logistic regression model to account for unobserved heterogeneity potentially resulting from crash under-reporting, operational and geometric features, and human behavioral factors. Factors associated with increasing probability of fatal pedestrian injury include crashes that occur on high-speed roads, at intersections, during darkness, and that involve heavy vehicle-pedestrian collisions. Drivers who are less educated were more likely to be involved in fatal crashes involving pedestrians. Interestingly, pedestrian injuries are more severe when a car is driven by family, friends, or relatives as compared to a vehicles owner. The detailed findings of this research are contrasted with findings from developed countries, and their implications are discussed in relation to infrastructure and policy interventions.

Investigating pedestrian injury crashes on modern roundabouts in Addis Ababa, Ethiopia

Pedestrian crashes represent about 40% of total fatal crashes in low-income developing countries. Although many pedestrian crashes in these countries occur at unsignalized intersections such as roundabouts, studies focusing on this issue are limited. The objective of this study was to develop safety performance functions for pedestrian crashes at modern roundabouts to identify significant roadway geometric, traffic, and land use characteristics related to pedestrian safety. Detailed data, including various forms of exposure, geometric and traffic characteristics, and spatial factors such as proximity to schools and to drinking establishments were collected from a sample of 22 modern roundabouts in Addis Ababa, Ethiopia, representing about 56% of such roundabouts in Addis Ababa. To account for spatial correlation resulting from multiple observations at a roundabout, both the random effect Poisson (REP) and random effect negative binomial (RENB) regression models were estimated. Model goodness-of-fit statistics revealed a marginally superior fit of the REP model to the data compared with the RENB model. Pedestrian crossing volume and the product of traffic volumes along major and minor roads had significant and positive associations with pedestrian crashes at roundabouts. The presence of a public transport (bus or taxi) terminal beside a roundabout was associated with increased pedestrian crashes. Although the maximum gradient of an approach road was negatively associated with pedestrian safety, the provision of a raised median along an approach appeared to increase pedestrian safety at roundabouts. Remedial measures were identified for combating pedestrian safety problems at roundabouts in the context of a developing country.