A state appeals panel has ruled that the city of Chicago must post signs informing drivers about street cleaning at least 24 hours in advance of ticketing them. But the panel’s decision could cost the plaintiff tens of thousands of dollars in attorney fees.The 1st District Appellate Court on March 11 found that the city’s street-cleaning ordinance is potentially unconstitutional because it does not require a reasonable period of time to elapse between when a posting notice is made and when the street cleaning …