Some service stations in New South Wales have begun imposing their own caps on fuel purchases.Rural and regional communities were first impacted by fuel shortages and disruptions to supply, but it appears the crisis has widened to cities.On Sydney's Northern Beaches, a petrol station has posted a notice at the bowser telling customers it has had to introduce a 50-litre limit on each vehicle.LIVE UPDATES: Albanese seeks to reassure nation on fuel crisisOn Sydney's Northern Beaches, a station has posted