Officials are contacting more than 200 landowners whose properties are in the way of a just-revealed route for an Auckland inner city rail link.
Auckland Transport today released its preferred path for the City Rail Link, which is expected to cost up to $2.86 billion.
It extends the rail line through Britomart, under Albert, Vincent and Pitt Streets, then beneath Karangahape Road and the Central Motorway Junction to Symonds Street before rising to join the western line.
Authorities would need to buy property from 210 owners to secure the route, Auckland Transport said.
Underground land from 70 interests, including 12 unit title developments with multiple owners, would also need to be purchased for the tunnels and stations, it said.
Auckland Transport chief executive David Warburton said officials were now informing landowners whose properties would be directly affected by the route.
"Our focus is on protecting a route... We first want to work with landowners to help ensure they are well informed and to help us understand their issues. Property purchase is a second step."
Auckland Mayor Len Brown said the route identification was a big step towards the completion of "one of the most important public transport projects" in the recent history of Auckland.
"The CRL won't just provide a convenient train line below the city centre. It will unleash the potential of the entire suburban rail network, increasing frequency, reliability, and speed of trains across all of Auckland."
The rail link would be built in two 3.5km long, twin tunnels up to 45 metres below the city.
It would make Britomart a through station rather than a dead end, allowing faster, more frequent and reliable train services, Auckland Transport said.
The CRL would also provide three additional city centre stations at Aotea Centre, Karangahape Road and Newton and an interchange adjacent to New North Road, Mr Warburton said.