Cycle shopping
The trick is to buy small amounts each day on your way home from work. That also lets you pick fresher food, or half-price food on its smell-by date. It reduces the chance that something will go off because the week passed and you did not need it. Personally I prefer a bus because it is hard to read a book while riding a bike. The subsidy is worth it. If some of the passengers had to drive (or ride a bike) everyone else would have a really bad day.