The day I stopped traffic

Oh mine!
To my left a green light,
To my right, cars move.
And straight ahead…
A line waiting for the hault to expire.

I… I’m blocking road and my red steed dressed up in scratch.
But polite I won’t,
Since this is the exit I reckon.
And my four meters of length,
Somehow, must go and squeeze in there.

My win of today!
I was mightier than traffic light.