Why isn't there a junction 31 on the M4?

Question

Sensible and/or logical answers would be appreciated - ta

Answer 1

When they build new motorways the planners look at the Strategic Development Plans for 30 years ahead.

These will already have highlighted areas for residential, commercial and industrial growth etc.

If a new motorway is going through an area which is planned for major housing development, the road planners will leave space for a motorway exit and will leave out a junction number for future use.

Another good example of this is the M27 along the south coast. It jumps directly from J5 at Southampton Airport to J7 Bitterne. The missing junction (J6) will actually be built around 2012 once all the spare land to the east of Southampton Airport is finally developed and joins up with Botley and hedge End.

Answer 2

Some where past Cardiff I think - will update this in a couple of minutes with an accurate answer

[edit]
Aah, I've just read your question properly this time..,.

It's usually because they planned to put a junction there at some point in the future, but have since decided against it. Junctions 30 and 32 are only 5 miles apart so it was probably deemed unnecessary.

Answer 3

We missed our junction around about there so we went to the next one turned back onto Mway to get off at missed junction only to find ther wasn't one on that side, it put nearly an hour on our journey as we didn't know area!

Answer 4

They obviously planned to have one - probably where the A469 crosses - but never got round to building it.

Answer 5

There was, but it was closed because it was thought to be to dangerous,

but there is one on the A20, just as you approach Limoges in France

Answer 6

Well.Hmmm......