A doctor is calling for harsher punishments for people who keep their car engine running, saying that it would help to clean up the air. New rules in Brighton have dictated that drivers who leave their engines running when parked risk a £40 fine, with fines falling to £20 if paid within 10 days. Signs were installed across the city in December with enforcement starting at the start of this year. Motorists can be slapped with a fine if their idling cars are in a parking bay, taxi rank and other parts of the road, although the rule does not apply to sitting in traffic. Daniel Roberts, an A&E doc…