Venice, the city of waterways and canals, is to clamp down on pedestrian traffic during this year's carnival.
Bridges and narrow streets will become one-way routes
The Italian city is introducing a one-way system over bridges and in narrow streets, with stiff fines for revellers who ignore the rules.
On-the-spot fines of 25 euros (£17) could rise to 500 euros (£340) for those who fail to pay up.
More than 500,000 visitors are expected at the carnival, which runs from 7 February until Shrove Tuesday.
The last day of the carnival is expected to be the main attraction when thousands dress up in carnival costumes.
Venice police chief Francesco Vergine said that, in general, tourists were fairly obedient.
"When they are asked to go in one direction, they do as they are told by police, even if grudgingly," he said.
The theme of the festival this year is The Orient Express, Voyage on the Old Silk Road, India, Thailand, China and Japan.
Organisers say landmarks such as the Grand Canal and St Mark's Square will be "invaded by sounds, voices, dances, acrobats, street artists from the East".
Are you in Venice for the carnival? Tell us your experiences using the form below.
Disclaimer: The BBC may edit your comments and cannot guarantee that all e-mails will be published.