I've been visualizing a shot like this for quite some time now. The idea was to use a slow enough shutter speed to show the motion of the city while focusing on someone who was completely still. In order to do this, image stabilization was helpful. This makes it possible to hand hold down to 1/15 of a second while still keeping part of the image sharp. I'll likely explore this technique more in the future and encourage you to give it a try as well.