I bought my lights with the idea of being able to see where I am going - the road between Staveley and Windermere is unlit.
However, the traffic from behind on Bannerigg is doing 40 - 60 mph, while as a cyclist, the uphill drag reduces your speed to 5-7 mph (once you have run out of momentum from the downhill).
Anyone coming up you behind NEEDS to know you are there for YOUR safety. Lots of moving lights/reflectors are more eye-catching than one - such as a reflective tabard.
An adequate set of lights which enable you to be seen can be had for less than ten pounds. It's money well spent if you venture out in the dark/twilight.
