Hi Simon,
I have to say that no.2 really stands out for me.
I think you've got the composition spot on. Some really strong leading lines with the road and the barrier that take my eye right into the picture and the moving cloud detail in the sky has come out really well.
Personally, I also love the fact that it's not quite full dark.
As much as I like the "night-time" feel that you normally see with light trails I think it's really refreshing to see something different - combining the light trails with what appears to be a day-time scene and the extra detail that's given you has added another dimension that you don't normally see in these sort of shots.
from me.