I've only ever ridden in the daytime, but soon it will be getting dark earlier. Some days I find myself getting home much later which isn't a problem now, but will be as it gets dark out earlier. I broke down and bought a Planet Bike front and tail light yesterday at REI. (I was also looking seriously at the road bikes). I just want to be safe. I plan on wearing my reflective vest too. So here's a dumb question. One of the settings on each light has a strobe or flashing effect. Why would I need or use that? Just curious. You can tell I'm a newbie.