Methods of Green Time Allocation for Pedestrians under Saturated Signalized Intersections
Creators: name: Tewfik Suleman Wassie
Publisher: name: National Academic Digital Repository of Ethiopia
Year: 2020
Subjects: Pedestrian, Crossing speed, and Start-up time

description: Roads, a way of expressing ones country development now become a source for one of the<br> worst news we hear in our everyday bases. Every year two and half million intersection<br> accidents happen and about 20% of collisions were fatal. Pedestrians are the most<br> vulnerable road users and 62% of daily travel mode is token by walking in Addis Ababa. In<br> this city pedestrian’s interaction with the vehicles happen in most of the signalized<br> intersections, therefore it is necessary to update our timing strategies by considering our<br> local conditions. In this paper, three four-leg signalized intersections with different<br> geometrical elements that will affect the pedestrian movements were selected to understand<br> crossing speed and start-up time of the pedestrians. Video was recorded at the intersections<br> to get pedestrian characteristics and timing plan of the signal lights. In addition, field<br> measurements was taken to determine the crosswalk length and width. From the video a total<br> number of 1732 pedestrian characteristics data during a peak hour from the six-legs (2 in<br> each intersection) was manually extracted later this data was divided in to 80% for training<br> data on which the models was developed and on the remaining 20% the validation of the<br> model was done. A common variables including Gender, Signal Timing, Curb Height, Age<br> Group, Movement Type, Group Size, Crosswalk Length, and Crossing Location were taken to<br> develop a models and additionally interaction within the movement were considered for<br> Crossing seed model and Interaction at the start of movement were considered to develop a<br> model for Start-up time for pedestrians. Independent sample T-Test and one way ANOVA is<br> used to identify the factors that significantly affect pedestrian crossing speed and start-up<br> time. MLR model was developed after checking the assumptions and the results indicate that<br> Gender, Crossing Location, Age Group, Movement Type, Group Size is found negatively<br> correlated and Signal Timing, Curb Height, and interaction within the movement is positively<br> correlated with crossing speed with R2adj= 89.5% for condition 1 and for condition 2 the<br> remaining will be the same except interaction within the movement is removed and crosswalk<br> length is found significant and negatively correlated with crossing speed with R2adj= 86.1%.<br> Gender, Age Group, Group Size, Crosswalk Length, Curb Height, and interaction at the start<br> of movement were found inversely related with start-up time.<br> Finally, MLR models were developed using significant variables and the results were<br> compared with previous studies and the result shows the developed model have higher R2adj<br> than the other model in predicting the characters of our community. Also, green time<br> allocation methods were compared and the updated green time allocation HCM method<br> which use 0.97556 m/sec than 1.2 m/sec which was assumed by HCM is recommended to be<br> used in this paper