Illegal parking in and around a newly-renovated market area in Lincolnshire has prompted a warning from officials.
Boston's Market Place reopened after a £2m change to a "shared space", or one without defined roads and pavements.
Boston Borough Council has now said inconsiderate parking was causing problems for buses and deliveries.
The county council takes over parking enforcement from the police this autumn and officials said any "perceived honeymoon period" would soon end.
Problems have been reported all over the town but attention has focused on the Market Place.
The borough council said some drivers here were ignoring clearly marked parking bays - but admitted rows had broken out when the bays were covered on market days.
Derek Richmond, the council's portfolio holder for car parks, warned drivers the rules had to be obeyed.
"Any perceived honeymoon period will soon be over," he said. "On-street parking will be enforced.
"We are sounding this reminder now so that motorists still have a little time to adopt better practice and get used to the idea that stricter car parking enforcement will be coming to Boston."
Local police said they had handed out 120 tickets in one street alone but were combining this with education over the new Market Place system.