Leider schmeissen viele Leute ihren Müll auf die/der Strasse.
Saw this question on the facebook page of deutschewelle, the answer seems to be die. I dont understand why, we are throwing something to the street so its like giving smth to someone. Shouldnt this be dativ and result in die turning to der. Can some explain this to me?? Thx in advance.
"Sie schmeißen den Müll auf die Straße" is correct.
Here, accusative is used because the verb indicates a movement with direction. -- Toward the (bottom of the) street.
Perhaps this can make the use of dative or accusative with the preposition "auf" clearer:
Ich fliege auf den Mond. (I'm flying to the moon) -- Accusative, because I'm moving toward the moon.
Ich gehe auf dem Mond spazieren. (I'm taking a walk on the moon) -- Dative because I'm moving within one location (on the moon).
Edit: You wrote that dative should be used because the street is the recipient. This ""recipient" = dative" idea is correct if there is no preposition.
Example. Ich gebe meinem Vater das Buch.
But if there is a preposition, the cases have to follow the requirements of that preposition.