Games : Show the direction of one-way roads

In Cities: Skylines, how do I easily show the direction of one-way roads?

When I'm building a city and I want to use one-way roads, it's hard to spot from a distance what direction a road is going, unless I zoom in until I can see the arrows on the actual road itself. Or if I pay attention to the flow of traffic, if there even is any traffic on the road.

SimCity clearly indicates the direction of one-way roads, for instance.