To start the animation, click the 'Play' button in the ribbon toolbar. The vehicles may take a couple of seconds to appear.
The speed is set automatically, based approximately on the width of the lane. Vehicles in the centre of the road will also travel slightly faster than those near the edges.
Please note this is not meant to simulate real traffic flow - it is only an illustrative animation of what the character of the street might be like.
You can set the Direction of all Vehicle Lanes and Bus Lanes in the Streetscape Elements Input Panel.
If you reduce the size of the window, the spacing between the vehicles will be reduced, but if you let the vehicles run for a few seconds, the spacing will return to normal.