This study presents a comprehensive methodology to improve monorail route selection in Kirkuk city, Iraq using a quantitative GIS-based multi-criteria decision analysis. The primary aim of this study is to develop and apply a quantitative, GIS-based multi-criteria decision analysis framework for optimizing and objectively selecting the most suitable monorail route in Kirkuk city, Iraq, by integrating spatial, topographic, accessibility, service coverage, and economic factors in order to support sustainable and cost-effective urban transport planning in a post-conflict context. The research area covers 460.89 km², including an extensive road network of 5,533.27 km and 3,193 points of interest (POI). Four different monorail routes were analysed and evaluated using OpenStreetMap data derived from an analytic hierarchy process, digital elevation models and site suitability analysis. The approach uses weighted graph construction, various shortest path methods, and a wide range of performance metrics, including cost-effectiveness, service coverage, topographic conditions, and accessibility. Route optimization includes terrain suitability (scores from 0.50 to 0.78), elevation profile (288–393m), gradient limitations (maximum score 0.20 to 0.32), and points of interest (POIs) within a service radius of 500 m to 1 km. Based on this, Results shows Route 1 is the ideal choice as it found to be the most economical route (4.15 km, US$214.01 million), had the highest suitability score (0.70), and required the shortest travel time (9.61 minutes). On the contrary, Route 0 had the widest service coverage (31.37 km² service area, 66.1 points of interest within 500 m).