Mythical M18 junction?

[james_tigerwoods]

I've driven on the M18/M180 regularly (almost daily) for about 5 years and I have often wondered this:

Just after the M180 junction (or just before the M180 junction, depending on your view) on the M18, there seems to be a "feeder" lane for a junction that isn't there - is this a junction that's been removed or one that was planned, but never built?

Here:

http://g.co/maps/anmxq

JTW