Autostrada Roma - aeroporto di Fiumicino

The A91 is an 18.5-kilometre motorway in the Lazio region, linking central Rome to Leonardo da Vinci International Airport at Fiumicino and serving as a feeder road to the Grande Raccordo Anulare ring road. Opened in 1959, it is one of Italy's early postwar road infrastructure projects, managed by the state road authority ANAS. Despite receiving its official A91 designation only in 2000, the route's green signs still display no number — only the distinctive green octagon with a plain letter A.