The best way to visit the historic area and downtown is on foot. Most attractions are located at walking distance from each other. Besides, the traffic is quite heavy and disorganized so renting a car or taking a taxi would be a waste of time and money. Taxis are all white, with yellow and black stripes. Don't take any other taxi, because they are illegal.
Public Transport bus is always a good choice. There are around 40 bus lines, which drives to downtown. A one way ticket cost ARP 2 about 0,50 U$S and must be payed to the bus driver on coins. Bus lines 102 and 118 goes to Yerba Buena, an beatiful touristic destination in Tucuman Metropolitan Ãrea. Bus 118 can be reached in Santiago del Estero street north of the center while bus 102 on San Lorenzo street south of the center. A ticket from Center to Yerba Buena costs 1,80$. Bus line 121 to the Airport can be reached on Av. Avellaneda and Av. Gobernador del Campo. A one way ticket costs 1,60$. Just one every hour.