Does it lead to a lack of congregation on the roads? (7,5)
I believe the answer is:
traffic light
'roads?' is the definition.
Although both the answer and definition are singular nouns, I don't understand how they can define each other.
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for traffic light that I've seen before include "Vehicle flow controller" , "one wants it to be green" , "A shining contribution to road safety" .)