As most pensioners don't have jobs to go to, then why not restrict them to shopping only between the hours of 02:00 and 05:00 - that way they don't get in the way of us normal folk. It also has the benefit of making sure they are only on the road when most decent folk are tucked up in bed.
As soon as people reach 60-65 they should be forced to operate in "nocturnal hours" so we don't have to be infuriated by their slowness and acrid stench