Yes, it is illegal but I've been running that way for several years. I did it mainly because I felt the Givi topcase buried the tail light more than I wished. So I bought a device that has the turn signals act as running lights, that then flashes several times when a brake is applied, and then acts as a brake light as well... all the while still acting as a turn signal. The little magic electronics can be seen at
Sound Off Recreational, Inc. - Safety Lighting Products. The so-called Priority Plus works fine and is easy to install. I've been told by several forum folks on group rides that they like the effect.
