What does the cryptic crossword clue "Danger, by the way, for those over 70 (5,4)" mean?

The definition is "Danger, by the way, for those over 70". The wordplay uses a cryptic definition. Cryptic definition The answer is SPEEDTRAP.

Danger, by the way, for those over 70 (5,4)

Guardian Cryptic #29611 | 4 Down | 2025-02-06 flower