Friend of mine was driving down the road one day, and someone in the lane next to him turned on her turn signal, then merged into him without looking. She explained the situation carefully to the adjuster, noting that "she had her turn signal on, therefore she had the right to merge." At this point, the adjuster contacted my friend and asked where to send the check.
A turn signal does not give you the right to the lane. You have to look, there has to be enough room.