thanks for the advice, but it was my understanding that if you "don't" have the extensions then the traffic control missions would not spawn. Have no extensions and still get them. To do as you suggest for 100s of stations in order to spread them out is way too expensive.
i believe the extension was added in response to players talking about the specific traffic control units, but I had the need for the trained staff before they added the extension/ units. and as an alternative in stations you have fd utility, train them in traffic control, or 2 out of 3 in the chief unit, and can always train all your patrol units in it too ( though I really can't understand why pd needs the training in the first place I always thought it was a part of their normal initial academy training)