The growth in economic activities has led to an increase in car ownership, contributing significantly to traffic congestion in modern urban areas. The study investigated the impact of multi-story parking facilities on traffic congestion and environmental performance at three critical intersections in Baghdad: Al-Khulafaa, Al-Ameen, and Al-Maidan. Under existing conditions, all intersections suffered from high congestion levels, long delays, low travel speeds, and high emissions. Field data were collected using Metro Count devices and analyzed through SIDRA Intersection v9 software under two scenarios: the existing conditions and an alternative scenario incorporating structured parking and improved traffic control measures. Comparisons were made using key performance measures, including average vehicle delay, queue length, travel speed, fuel consumption, and pollutant emissions. In the alternative scenario, the findings showed significant improvements: travel speeds virtually doubled, queue lengths decreased by over 70%, and vehicle delays decreased by up to 87%. Additionally, all sites had a greater than 70% decrease in CO₂, CO, HC, and NOₓ emissions as well as annual fuel usage. The results show that drivers seeking open spots and on-street parking are the main causes of traffic congestion. The study concludes that incorporating multi-story parking facilities into urban traffic planning is a very successful way to increase mobility, reduce environmental impact, and boost the overall effectiveness of the road network in crowded central regions.
Abood et al. (Mon,) studied this question.