This is particularly useful as it identifies spillages going north of Ballacraine. It may suggest an overfilled, left-sided tank, slopping it out on right-hand bends. However, the spillages that we saw were towards the middle of the traffic lane.

In response to a suggestion that rain had brought old spills to the surface, this certainly happens, and on a frightening scale. However, yesterday's spillage was very strong, visible and concentrated. We first noticed it from Ballagarraghyn to Ballacraine, and queuing for the lights had caused larger deposits there. I would also guess that it had been dropped between 4pm and 5.15pm, when we spotted it, as there was little spread pattern caused by traffic and/or dampness.

If you are travelling that way this afternoon, keep your eyes open for a repeat performance.