Why can’t I get to Route 12?

Question

I’m playing Pokémon White and just defeated Iris in Opelucid City . But for some reason I’m blocked from Route 12 and I need to get there in order to get the Heracross I need for my team. Please Help!

Answer 1

In the original Black and White, Route 12, as well as most areas in Eastern Unova, cannot be accessed until after completing the main game, so unless you have someone to trade with, you will have to wait until after completing the Pokémon League.

Source: Experience