Nexusmods user, Nayef_k93, has created a Resident Evil 3 expanded map mod that allows players more early exploration in the game.

This mod, called More Investigation, removes barricades and other items that prevents the player from exploring the downtown area in the game’s opening.
Created by ‘Nayef_k93’, the More Investigation modification for Capcom’s latest Resident Evil installment on PC and consoles removes barricades, items and other stuff that prevents you from exploring Raccoon City’s downtown area in the game’s opening level. This brand-new mod allows players to explore the downtown area right at the start of the game, thereby making the game feel more open.
This mod also includes pathfinding AI for Nemesis.
You can download the Resident Evil 3 More Investigation mod for yourself over on Nexus Mods.