I want to formulate a problem in CPLEX OPL where a vehicle travels from a source node (road junction) to a destination node (road junction) while making a mandatory stop at one intermediate location. There are six possible intermediate locations, and the vehicle must select exactly one.

The objective is to determine the optimal path and intermediate location such that the total travel time is minimized. The time horizon is divided into 48 slots, with traffic conditions changing every 30 minutes. Consequently, the travel time on each road segment varies based on the traffic flow at a given time slot. Additionally, the travel time on each road is always less than the slot duration.

How can I model this problem in CPLEX OPL while considering dynamic traffic flow conditions?