DT puzzle extra �500 (sun. 25th)

[bionic woman]

know the duo but cannot solve 5d land collapsed into the
sea -s-o-i-
22d journalist and would-be groom to accept plot -m-e-i-0-
50a cross-carriageway traffic diversion

[sedge47]

5d. Estonia (anag. into sea)
22d. su bed itor

[bionic woman]

many thanks sedge4 - never thought of anagram! thought it was something mythical like 'Astoria' (learned a lot about the Waldorf!!) Sub edtior eluded me 'cause I spelled 'Innumerable' wrong . Ah! me, I do these xwords to keep my little brain working - I must be wearing it out.
hoping to get an answer for other clue which stumped me, but again, thanks a bunch.

[johnalex]

50a What letters do you have?

[bionic woman]

sorry johnalex Have you seen my answer to sedge 47 I must be more stupid than I suspected. 50a letters are:-o-t-a-l-w

[standian]

contraflow

[dr b]

50a, contraflow

[bionic woman]

dr b many thanks to you also. Am greatly relieved that it was a motoring term - (I only drive like Hyacinth Bucket, at least my husband says after almost 60 yrs. as his passenger!) I I could hardly be expected to know traffic-speak.
to you all, Sedge47, johnalex and yourself dr b I am only sorry the star ratings only go to 3 -they don't have a rating for "superb"