These types of immages, or long exposure times for moving lights, is how I first learned about shutter speed and exposure times. There's a bridge in my neighborhood that goes over a freeway and my friends who are into photography took some photos of the car traffic at night time with a long exposure time. I'm sure many others have seen these types of photos too. When I saw them for the first time I thought they were super cool and wondered how they did that, which caused me to look it up and learn about shutter speeds/exposure time