The most common and most likely answer to this crossword clue is the 10 letter word EXPRESSWAY
I've seen this crossword clue in The Times
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More clues leading to the result EXPRESSWAY
Buddy explains!
The straight part
We know that "trunk road in the US" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case trunk road in the us = expressway.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.
What does EXPRESSWAY mean?
EXPRESSWAY noun- A divided highway where intersections and direct access to adjacent properties have been eliminated.
- (parts of the US) A road built to freeway standards.
- A road built for high speed traffic, but not up to motorway standards or designated a motorway.