At Kiel Main Railway Station (Hauptbahnhof) take the bus Number 41 (to Tannenberg) or Number 42 (to Suchsdorf) and get off at the bus stop named "Institut für Weltwirtschaft" (Institute for the World Economy). The ride will take about 12 minutes.
Follow the street for 50 metres keeping the firth to your right. Diagonally across the intersection you will see the sweeping front of the ZBW building.
The autobahn A215 Hamburg-Kiel ends at the Westring (1st traffic light). Drive straight ahead (on the Schützenwall) and follow the signs for "Zentrum-Fähren". After approx. 2.3km, (6th traffic light, you are at the Exerzierplatz parking lot) make a right turn and drive to the waterfront (0.6km). Turn left into Kaistraße and keep going. It changes its name to Düsternbrooker Weg. Continue straight ahead until you reach the Kiellinie where you turn left to reach Düsternbrooker Weg 120.
A taxi ride from Kiel Main Railway Station (Hauptbahnhof) to the ZBW in Kiel will take around 7 minutes.
You can reach the ZBW in Kiel on foot from the Main Railway Station (Hauptbahnhof) in around 45 minutes. Pass through the shopping centre "Sophienhof". When you exit you are in the pedestrian area of the Holstenstrasse. Walk straight ahead until you reach the "Alter Markt", follow the "Dänische Strasse" and from there pass through the "Schlossgarten". From here you can see the Firth of Kiel and cross over to the promenade called Kiellinie. Follow it northwards, keeping the firth on your right, until the library comes into view on the left side (where the promenade meets the road again).