The study delves to estimate the fastest route for courier vehicle routing in Dhaka city for different times of a day. It identifies the fastest route through Ant Colony Optimization (ACO) considering real time traffic scenarios. ACO mimics forging behavior of ant colonies to search for the route among various paths which requires minimum travel time. The study road network comprises with five locations, i.e. nodes which are interconnected with links i.e. roads. Travel time requires for each link are estimated and total travel time requires for different routes under four times of a day, such as, morning, afternoon, evening and night time are estimated. The result shows that optimized route obtained by ACO can decrease travel time by 6.12% to 18.37% and delay by 13.64% to 40.91% compare to those of actual route. Night time (7:00-10:00PM) trip requires the lowest travel time and less delay compare to other times of a day, and hence, courier vehicle routing should be scheduled accordingly. The proposed technique in this study can be incorporated with large scale transportation route planning and scheduling.