Have you ever driven along the M53 and wondered what that half-built junction is between junction four and five? Or wondered why the road changes from a spaced-out rural motorway to a squashed up two-laned bypass? No, most people haven't, but there's a bit of a story behind it and that is explained here:
In the late 1960s a road was planned from the Mersey Tunnels to the west of Chester, probably to come out somewhere near the present-day A494/A55 junction. The first part was built, as a three-lane high-standard motorway getting traffic out of Liverpool, through the Wirral and to where the ghost junction is today. From here, there were temporary links to the A5032, the fully grade-separated bypass for Chester and Ellesmere Port. The A5032 started life out as an unclassified road, so even though it was an almost entirely free-flowing journey it wasn't a very high standard one.
Anyway, whilst things were being prepared for the rest of the M53, the A5032 couldn't cope with all its new traffic, so it was upgraded to motorway, the M531. Even though it had very close and ridiculous junctions, it was decided it will become a spur of the M53 when it is finished. In the meantime traffic flowed straight from the M53 on to the M531.
After that, nothing happened. The M53 wasn't extended, and plans were soon forgotten, so in the 1980s the M531 was renumbered to M53. It was extended a little bit too.
This explains the unfinished junction (it was originally so that the A5032 could take the M53's traffic until it was finished, and then it became the M53/M531 junction-to-be). It also explains why the M53 loses a lane, and then drastically changes.