Hi vas111, yes it's technically not required (except in some instances, e.g. where other transport methods do not treat the road as one way), but it doesn't do any harm. I tend to add the forward/backward tags habitually as I'm working on other items nearby, as it means I'm always applying the same standard whether it's on one or two-way roads, and with the more consistent view gat results, I'm able to more easily spot any errors I've made. This changeset wasn't specifically to add directions to traffic lights, but to ensure they were mapped on respective ways rather than on both nodes at the intersection, which results in any routing across the junction on the single carriageway "seeing" two sets of traffic lights instead of one. But I did add the directions as a by-the-by.