Paper Title
Optimization of the Public Transport Network For a Multiple-Core City: Case Study of Kabul

Abstract
Kabul is the capital city of Afghanistan with massive expansion of population since 2001. By 2025 Kabul�s population is projected to increase by 1,247,933 inhabitants. This growth will not be only in the inner city, but with more growth rate in the regional cores, affecting structure of the city morphologically as well as functionally. Before 2001, Kabul was a monocentric city with a dominant city inner city. Nowadays due to rapid growth of population, Kabul needs to be transformed to a polycentric city. The fact that Kabul is becoming a polycentric city (with stronger regional cores) makes it necessary to adapt its public transport network. Nowadays, 60% of the trips between regional cores are done by cars causing more congestion, air pollution and high user cost. To overcome this problem, it is most likely to improve the public transport system to attract more people to use it. So, here we will study the idea to propose a new line linking the regional cores to each other using the VISUM demand modeling software. This new line pretends to strengthen the regional cores and create a more polycentric public transport network. Two alternatives will be studies as: Alternative-1 follows the present planning of the lines in the city and regional cores with buses with a distance between stops of around (300-500) meters. The alternative- 2 shows planning for polycentrism, with around 900 meters distance between stops and a speed higher than alternative one. Furthermore, different available routes will be studied for the alternatives. Finally, all of these sub alternatives and alternatives will be compared between each other as well as with the reference scenario to find that one which will improve the multi-core structure of Kabul effectively. This will be done based on the minimizing the total weighted PJTs for each zone. The results and analysis show that the new proposed line increased the maximum number of passengers from 598 to 1864 persons per four hours, mean speed from 20 kmph to 30 kmph and decreased the Perceived Journey Time (PJT) by 327 hours. Keywords- Kabul, Public Transport Network, Headway-based Route Assignment, Multiple-core city, VISUM, Perceived journey time, capacity of the line.