A lop-sided bridge somewhere

A very dirty slide of a lop-sided bridge somewhere with a shop called 'G. G. Williams Calor Gas Sales & Service' in the background. In the extreme right hand side of the picture there is a car showroom with the back end of a car showing and that dates the picture to the late 1950s. I don't know why the bridge was made such an odd shape, or in fact, what it is a bridge over since there doesn't seem to be any reason for it - presumably at some point it covered a stream or railway line which, at the time the photo was taken had been removed.