Local buses operated by START (www.startromagna.it) depart from Piazza Farini (single/24-hour ticket €1.30/3) outside the train station. Punto Bus, also outside the train station (but poorly signed), provides bus information and tickets. From the train station, it's a 600m walk to the city centre along Via Diaz.
In town, cycling is popular (Ravenna removed cars from its city centre in 2016). Rent bikes just outside Ravenna's train station at Cooperativa San Vitale. Alternatively, use the free 'C'entro in Bici' bike-hire service sponsored by Ravenna's main tourist office: simply present photo ID and tourist-office staff will provide you with a key to unlock one of the free yellow bikes stored at racks throughout the city. Return the bike at least half an hour before closing time to reclaim your photo ID.
The main car parks are east of the train station and north of the Basilica di San Vitale. Parcheggio Giustiniano, in the shadow of San Vitale, is a good place to leave your car. For a comprehensive list of parking lots, see www.cesostapervoi.it/raggiungi-la-tua-destinazione.