MTR Corp. has built Hong Kong’s railways one of two ways: The government handed over land around new stations, or paid directly. Either way, the money arrived with the track.

The Northern Metropolis is different. MTR is putting up at least HK$38.9 billion ($5 billion), borrowing to do it, and will wait years to find out whether the land it receives in return —?under a funding model that has never been tested at this scale —?is worth what the lines cost.

“In the past, some projects we developed the area and then we built the railway,” said Dominic Law, the head of project delivery for phase one of MTR’s Northern Link. “But moving into the Northern Metropolis, we focus on the infrastructure first.”