Ah yeah, that makes sense. However, if all roads are fully jammed, most people would be able to walk to a grocery store - it's likely not insanely far away from you (quick search suggests average straight-line distance to a grocery shop in the US is ~4 km = 50 min, which sounds very far away from a non-US perspective but still not completely unreachable), it's just that usually there's a highway full of traffic between you and the store.