jungping,
lets not get confused.
forget what radial you are on....if you are being vectored then this will continue until normally the last vector you get will be for a 30 degree intercept...anything like your example would be too big a heading change (depending on how far you are out ) and not normal to allow you to intercept the localizer yourself without further guidance from radar.
if you are cleared for the approach this will only be given when you are about to capture the localizer or are already on it and then you are cleared for the published approach right to the ground. you may be told to call the marker just to remind approach or tower where you are..
the IAF is normally a term used more with non percision approaches as a reporting point rather than with a precision approach.
perhaps i misunderstand your question...
the dean.