Traffic had three top ten hits and one minor hit in the UK although they made little impact on the American singles charts. Their music is somewhat different from the Spencer Davis Group, which was a British R+B band. While R+B is one of the ingredients of Traffic's music, there is also some rock, jazz, psychedelia and traditional folk in the mix.
As far as the UK hits are concerned, Paper sun made the top five, Hole in my shoe made number two, Here we go round the mulberry bush (from the similarly-titled movie) made the top ten and their chart history ends with the minor hit, No face no name no number. Of these songs, a cover of Hole in my shoe (recorded for charity) made number two in the eighties, thus matching Traffic's original achievement.
Those hits are all here, together with some interesting album tracks, among them the title tracks to three of their albums (Dear Mr Fantasy, John Barleycorn must die, Low spark of high-heeled boys).
Buy this to get a feel for what Traffic is all about, but if you really enjoy at least some of the tracks, identify the albums which your favorite tracks originally appeared, then buy them. Their original albums were Mr Fantasy (1967), Traffic (1968), Last exit (1969 - recorded just before their temporary disbandment and it shows), John Barleycorn must die (1970), Welcome to the canteen (1971), Low spark of high-heeled boys (1971), Shoot out at the fantasy factory (1972), On the road (1973) and When the eagle flies (1974).
This compilation serves as a great introduction to Traffic's music but can't do them full justice. Only the original albums (except Last exit) can do that.