There are multiple artists with this name: 1) Traffic were an English rock band.
2) Traffic is a poprock band from Estonia. 1) Traffic started out with Steve Winwood, Dave Mason, Jim Capaldi, and Chris Wood after Winwood left The Spencer Davis Group. From their beginning, in 1967, they were quite popular in their native England, though success elsewhere was slower in coming. Their first three albums combined psychedelic rock and soul with elements of British folk music, giving them a unique, groundbreaking sound.