Following subsequent decisions, new trolleybuses were purchased in the late 1990s and additional vehicles in the mid-2000s, and physical work to reopen route 4 of the former system began in 2008 and was completed in 2011,[4][5] but the project never came to fruition.

[6] Construction of the renewed wiring and substations along route 4 was completed in 2011, and eight new trolleybuses were in stock by 2009 – five built in 1997 and refurbished (after more than a dozen years in storage) around 2010 and three brand-new trolleybuses delivered in 2009–2010 – and the vehicles made test runs on the refurbished line in 2010[7] and later, but the rebuilt and re-equipped system never opened, and no explanation was given by local authorities.

[8][5] Meanwhile, an extensive length of overhead trolley wiring that was never part of the project to reopen one route as trolleybus remained in place in the mid-2010s, despite being unused for decades, but in 2021 the city council approved its removal.

[1][3] It was constructed by the Compagnia Elettrotecnica Italiana (Italian Electrotechnical Company) but managed by SAER [it] (Società Anonima Esercizi Riuniti Elettrica Nazionale).

A significant expansion occurred in March 1952 with the conversion to trolleybuses of route 4, from Bari to Carbonara and Ceglie del Campo, a distance of 7 kilometres (4.3 mi).

[1] On 1 September 1975, the entire system was shut down indefinitely due to a serious breakdown of an electrical substation[11] and service remained suspended for more than three years.

[1] In 1990, persuaded by the allocation of government grants for projects that would reduce pollution, the municipality and AMTAB decided to reopen trolleybus line 4.

[1][16] The work was contracted out to Breda Costruzioni Ferroviarie, which was to rehabilitate the electrical power system along route 4 and provide five new dual-mode trolleybuses.

The legal dispute between the municipality/AMTAB and AnsaldoBreda was finally resolved in 2005,[17] but little or no progress toward the planned reopening of the trolleybus system was made over the next two years.

[18] AMTAB became a joint-stock company (or S.p.A.) in 2003, and although the acronym form of its name remained unchanged, the letters now stood for Azienda Mobilità e Trasporti Autobus Bari.

In August 2008, a contract was awarded to a consortium led by the engineering firm SIRTI [it][14] to resume work on renovating the infrastructure and to supply three new low-floor trolleybuses, to be built by Van Hool.