Heavy traffic like this giving rise to understatement on article penned (4,2,4)
I believe the answer is:
nose to tail
'heavy traffic like this' is the definition.
I don't know anything about this answer so I can't tell whether it can be defined by this definition.
'rise to understatement on article penned' is the wordplay.
'rise' shows that the letters should be reversed in order.
'to understatement' becomes 'litotes' (I've seen this before).
'article' becomes 'a' (the indefinite article in English).
'penned' means one lot of letters goes inside another (inserted letters are enclosed or penned in).
'litotes'+'on'='litoteson'
'litoteson' enclosing 'a' is 'liatoteson'.
'liatoteson' back-to-front is 'NOSE-TO-TAIL'.
'giving' acts as a link.
Can you help me to learn more?
(Other definitions for nose to tail that I've seen before include "crawling along?" , "As cars in a jam" , "Like dogs meeting" , "(Of traffic) closely following one another" , "like rush-hour traffic!" .)