Just keep one thing in mind. Since it runs down your street maybe no one pays it much attention at all. But for you, it is an eyesore. Anything you plant there will only draw more attention to the ditch as your attention will be drawn there as you look at the plants.
Cattails will do fine if the soil just holds some moisture and doesn't go bone dry for months on end. While your thinking of pond edge plants, Pickerel weed might do very well too.
I do not think that plants there will upset your neighbors because it will look swampy, BUT they might be unhappy because they might think that it looks messy and unkempt.
