Sanral has told the Pretoria North High Court that complex economic policy decisions should be left to the experts and should not be second guessed.
A hearing resumed on Thursday into an application brought by the Opposition to Urban Tolling Alliance (OUTA) for an urgent interdict to stop the launch of e-tolling on Monday.
Proceedings are being watched by Finance Minister Pravin Gordhan.
OUTA argued that the entire e-tolling project is irrational and unmanageable.
It added the project was postponed before and that pushing the pause button one more time would do no harm.
An advocate for Sanral said delaying e-tolling would have a massive economic impact on the country and that the damage would take months to do with effects felt for years.
The judgment may now only be delivered on Saturday.