Many municipalities in Michigan have "public safety agencies." Especially in several of Detroit's more affluent northern suburbs (Huntington Woods, Oak Park, Berkley, Farmington, Bloomfield Hills, Canton Township, Fraser, Grosse Pointe city, Grosse Pointe Woods). This means their police and fire operations are a singular team. Public safety officers are cross-trained in law enforcement, firefighting and rescue. They have higher salaries. But these agencies are afforded with far greater staff flexibility and responsiveness. While under the public safety agency arrangement there are obviously still two separate vehicle fleets for different functions (patrol cars versus firefighting/rescue vehicles). But both fleets are technically police and fire vehicles. Hence the presence of red/blue flashers on Berkley's fire trucks. No idea if there are any other fire vehicle lights like this in Michigan.