Nashville's signal optimisation programme produced a stunning return on investment. Are those results exceptional? Could similar results be replicated in cities across the US and indeed the world? ITS International spoke to Chris Rhodes, P.E. of Kimley-Horn and Associates, project leader for the Nashville signal optimisation programme. "You have to bear in mind that with signal optimisation programmes you don't see, for instance, physical construction or new pieces of equipment on the roadside that someone