Cheers for the long comment~
If you wish to take delayed exposure photos of traffic lights which go in multiple semi-random directions, just jerk/spin your camera during the process. You will then have semi-control of the direction of light trails. This also helpful if your camera does not support long exposure times and you wish to have lots of trails (mine is max 8secs). Also, be aware than some lights naturally flicker which will leave strobed trails on the image.
Hope that helps, and welcome to dA