Hello, while it is perfectly acceptable to have traffic signal nodes placed on the intersection nodes (especially if you're adding them for the first time in a very quick edit), it is more accurate and representative of which roads/part of the roads are affected with the traffic signals on the stop lines, especially to routing systems that recognize traffic signals. This is especially important for four-way intersections along divided roadways. Generally, it is better to move signals to the more complex configuration than vice versa when possible.