The Oshodi Bus Interchange in Lagos State will process up to one million passengers daily when completed, an official said.
"What we are doing in Oshodi is the first of its kind.
"It is taking us a bit of time to put together because of the large size," the state Commissioner for Transportation, Ladi Lawanson, said in Lagos.
Mr Lawanson who spoke in an interview with the News Agency of Nigeria (NAN), said the state government had secured a commitment from contractors handling the project on its completion time.
"The timeline given for the completion is December, and we are optimistic that the terminal will be ready by then.
"If that is the case, we expect that by the first quarter 2019, we will start some activities there," Mr Lawanson said.
He told NAN that the government was set to roll out buses to service routes on the Oshodi-Abule Egba axis, with the arrival of 250 buses.
"In the last couple of months, we did the commissioning of the Ikeja Terminal which was meant to be the flagship.
"The Ikeja Terminal was signaling the beginning of what was going to be the entire project, consisting of 13 terminals including Oyingbo, Yaba.
"The first set of buses have come and we are using the Ikeja axis as a laboratory where we are going to roll out from," he said.
He told NAN that the routes for deployment of the buses had been procured.
"LAMATA - the technical arm of the Lagos State Ministry of Transportation - is involved in that.
"All the studies have been done and consultants engaged.
"By October/November, we expect the first set to roll out along that axis, but over 250 buses have arrived in Lagos," the official told NAN.
Mr Lawanson said that drivers of the buses had been employed and trained.
"Work is ongoing to make sure there are smooth operations.
"We are going to start seeing activities; we are going to start from Ikeja area and gradually move to the rest of the metropolis," he said.