The most common and most likely answer to this crossword clue is the 8 plus 7 letter word MOTORWAY MADNESS
I've seen this crossword clue in The Daily Telegraph
M
O
T
O
R
W
A
Y
M
A
D
N
E
S
S
Buddy explains!
The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.