Hong Kong drivers who leave engines running while they are parked could face fines under a new proposal to combat air pollution. The move is part of a package to be implemented this year. Diesel vehicles, a major source of street-level pollution, are expected to bear the brunt. At yesterday's Legco environmental affairs panel meeting, Deputy Secretary for Planning, Environment and Lands Kim Salkeld said the fixed fine for smoky vehicles would be increased this year, despite the proposal being dropped from the Revenue Bill this week.