By car
Through two main highways: the one connecting Milan to Genoa (A7, Pavia-Bereguardo exit) and the one connecting Brescia to Turin (A21, Broni-Stradella exit).
By train
From Milan Central Railway Station, there's a train about every 30 minutes (see trenitalia for additional info about costs and departure times).
By plane
From Linate Airport (LIN) The cheapest and easiest way to reach Pavia is to take the bus (15 euro for one way, 27 euro for both ways). It takes 60 minutes to reach the last stop (the closest stop to the city center), that is at Pavia railway station. You can check the time-table of departures from and to the Linate Airport online; you can purchase the tickets on the bus. A possible alternative is to take a taxi or a bus to Milan Central Railway Station and then a train to Pavia. There are several buses, private or public, about every 30 minutes, that leave from the airport to Milan Centrale railway station (www.atm-mi.it).
From Malpensa Airport (MXP) You can reach Milan Central Railway Station by train or bus (approximately 50 minutes), and then take a train from there to Pavia. To reach Milan Central Railway Station by train, you can use the direct train of the Italian railway system (http://www.trenitalia.com/) or the Malpensa Express train (www.malpensaexpress.it). Note that Malpensa Express train directly arrives into Malpensa airport, stopping at the basement level in Terminal 1. Terminal 2 (mainly low-cost flights) is connected to Terminal 1 (international flights) by a free 24-hour shuttle service. Otherwise, you can take the Malpensa Shuttle Bus (www.malpensashuttle.it) that leaves every 20 minutes. Taxis are also available for approximately a cost of 100 euro to reach Milan Central Railway Station or a cost of 170 euro to Pavia.
From Orio al Serio Airport (BGY) You can rent a car (www.rentalcars.com) or take a bus to Milan Central Railway Station, and then take a train from there to Pavia, or the shuttle bus (www.orioshuttle.com).