Taking long exposures and getting a photo that works can sometimes be difficult. Because the lens will be open to let the light in to get the proper exposure, you'd generally use a tripod to keep your camera steady so you don't get blur due to camera shake. If no tripod or a level area to rest your camera on is available, you'll have to shoot handheld and hope you don't get a lot of camera shake blur because chances are, you'll get them.
I shot this handheld with a Diana Mini and I was quite pleased with the result. The exposure was long enough that I let enough light in while still getting motion blur from the subway train moving into the station. You can also still make out the subway train if you pay more attention to the detail.
The one thing I'm disappointed in is not getting enough of the people that were waiting to get on the train. I was able to get some bodies but not full. The photo would've been more stronger if I was able to capture that but it still works.
"Redline subway car" / 35mm Ilford SFX 200 / Circa 2014