allow traffic in one direction only and can decrease traffic congestion. The direction in which the road is drawn also determines the direction of the traffic. Traffic will move from the starting point to the end point of the road. One way roads include Highways and Highway ramps, so make sure to place your highways in the right direction. Service vehicles cannot go against the flow of traffic and so even if a building next to a fire station is on fire if it is the wrong way down a one-way road the fire trucks will have to take the long route. Commercial and industiral buildings also require goods to be delivered and picked up, if they are unable to be serviced often enough on a one way road they may stop operating effectively.