ASSESSMENT OF THE IMPACTS OF MERGE CONFIGURATION,TRAFFIC DENSITY AND THE DISTANCE BETWEEN TRAFFIC SIGNS NEAR FREE WAY WORK ZONES ON DRIVERS’ RESPONSE

摘要

The effects of changes in merge configuration, traffic density and the distance between traffic signs in the advance warning zone on three driving parameters namely braking force, speed, and travel time are studied. A driving simulator study was conducted with thirty participants. The independent variables used in this study are (1) two types of merge configuration; conventional lane merge (CLM) and joint lane merge (JLM), (2) high and low traffic density and (3) three levels of distance between traffic signs; (i) standard distance, (ii) 25% reduction from standard and (iii) 25% increase from standard. The dependent variables used to capture drivers' response are braking force, speed and travel time. Additionally, each merge was divided into four sections for comparison. The results show that the effect of merge configuration on braking force and travel time was significant, but it did not affect the speed. The braking force in the JLM was 35% lower than the CLM. However, the travel time was higher in the JLM by 18%. The difference in braking force between high and low traffic density is about 40% for CLM and 20% for JLM. Travel time and speed did not show any significant difference with change in traffic density. The effect of varying the distance between traffic signs on braking force was significant, but it did not affect travel time and speed. The joint merge with standard sign placement resulted in the least braking force compared to others.