You intend to drive straight ahead, and the driver of the vehicle approaching from the opposite direction plans to turn left. Do you have the right of way?

Yes, you have the right of way. According to Art. 25 para. 1 of the Road Traffic Act, a driver turning left must give way to a vehicle approaching from the opposite direction and proceeding straight ahead. The visible D-1 'priority road' sign, along with the T-6a supplementary plate, confirms that both vehicles are on the priority road, which is why this general rule applies here.