Madaba sits on the King's Highway about 30 km south of Amman, and is an easy 45-minute drive. The simplest option is a taxi from Amman, which costs around JD 15–20 one way; many drivers will agree to wait three or four hours for a full day trip.
By public minibus you go from Amman's South Bus Station (Mujamma' al-Janub) to Madaba in about an hour for JD 1. Coming from the south, Petra and Wadi Musa are about three hours by car, and most travellers stop in Madaba on the drive between Petra and Amman. Queen Alia International Airport is only 15 km north — easier to reach Madaba directly from the airport than to go to Amman first.