Experimental investigations in circular tube to enhance turbulent heat transfer using various types of twisted tape inserts

الملخص EN

This paper reports on diagnostic parameters for pedestrian traffic safety problems using the Traffic Conflict Analysis Technique (TCT), particularly for pedestrian crossings at urban unsignalized intersections.

The method of study is based on the U.S.

FHWA-Federal Highway Administration guides for vehicular and pedestrian conflicts, applied using data collected from pedestrian crossings of several types observed in 4 critical unsignalized intersections in Baghdad city all of them located on the CBD area and experiencing high vehicular and high pedestrians volumes.

Regression analyses is performed to relate hourly pedestrian conflict to (hourly traffic conflict, hourly pedestrian volume, average pedestrian walking speed) as well as hourly pedestrian conflict / approach to (average spot speed, average pedestrian delay and approach width).

HCM 2000 manual is adopt to determine the average pedestrian delay.

Specific categories of countermeasures in geometric characteristics are suggested to improve pedestrian safety.

A developed model shows that, an extra increase of hourly pedestrian conflict can be represented by positive exponential model trend in relation with hourly pedestrian volume, hourly traffic volume, average spot speed and average pedestrian delay with coefficient of correlation range between 0.824–0.949, as well as a developed model shows that, an extra decrease of pedestrian conflict can be represented by negative exponential model trend in relation with average pedestrian walking speed with coefficient of correlation 0.921, on the other hand, it is found that, an increase of pedestrian conflict can be represented by positive linear model trend in relation with approach width with coefficient of correlation 0.837.In addition it is found that the higher coefficient of correlation 0.943 well get it when pedestrian conflict related with the hourly pedestrian volume and average pedestrian delay convened from all studied parameters (average spot speed, approach width, hourly traffic volume, average walking speed, average pedestrian delay and exit stop line).