Relatives of the victims of the 2012 Once train tragedy were all in attendance, prompting Macri to reflect on the "abandonment" on the part of the former Kirchner governments of train infrastructure.
The President claimed four decades had passed since the last major investment in trains and railways.
Current infrastructure projects "are not just to move from a hand brake to an automatic one" but to "move from the era of abandonment to the construction of a new reality, from corruption to transparency".
"Following the Once tragedy, the worst of several on our railways, some (former government officials) went to work on buying a lot of things without having any idea about how or why, without knowing how to maintain them or repare them", Macri charged, in a loose criticism of former Transport Minister under Fernández de Kirchner, Florencio Randazzo.
"Forty years have passed", he said, "that's more or less the the age of this young governor (Vidal). She would have been, can you imagine, in kindergarten", he pondered.
For her part, Vidal described some rail infrastructure projects as "things that aren't seen" but which form part of serious public works projects.
"This workshop will reopen in June. It will work to repair our trains and ensemble and put into work new ones", she said.
The Macri administration is expected to oversee the inauguration of as many as 770 public works projects in the run up to the October general and presidential elections, including sewage, paving and housing projects, according a report in Perfil.
As the election season heats up, the government plans to finalise 62 hydroelectric and water sanitation projects this year, a report in BA Negocios reported this week, citing sources close to the Infrastructure and Hydroelectric Secretariat.
Another 437 road works and 24 urban renovation projects are also scheduled for completion, according to sources at the Urban Infrastructure Secretariat, which also reported the planned conclusion of 25,000 new homes, 2,650 renovations, 22,445 utility connection tasks, and 248 general infrastructure projects.
The president, however, may not be present at all inaugurations.
"In some provinces, candidates prefer that he [President Macri] does not travel to support them, given his high disapproval ratings," the same sources told the same outlet.
Macri cancelled a trip to Santa Fe province next week after his candidate for the Cambiemos (Let's Change) coalition, José Corral, polled third in Sunday's primaries race, where Socialist former governor Antonio Bonfatti and Peronist lead candidate Omar Perotti look set for a face-off in June.
Macri spent Wednesday's International Workers' Day alongside Vidal and Mayor of Buenos Aires Horacio Rodríguez Larreta. The trio – who will all run for re-election in October – visited Lanús where they spoke of the need to strengthen "the culture of work" in Argentina.