The government has told international investors it wants their help deciding on the options for a second Waitematā Harbour crossing.Speaking to the Infrastructure Investment Summit, Transport Minister Chris Bishop said the government was commencing "early market soundings" on the project, and whether it will be a second bridge or a tunnel."Many of you will be from countries that have done mega-projects like this. It has been a long, long time since we have," Bishop said."We need your thoughts, and the lessons you have learnt being involved in similar projects."Bishop said the study would also ask about financing options, and expected tolling or road pricing would play a part.He said the first market sounding would take place in April, with a second one taking place later in the year.He expected to announce a preferred option in mid-2026."Auckland, and New Zealand, needs this project. And after decades of discussion, we are finally ready to put a stake in the ground," he said.The market soundings would involve one-on-one engagement with civil contractors, maintenance providers, investors, and debt financiers.They would be asked for their feedback on design elements and approach to delivery, as well as the market appetite and capacity.The New Zealand Transport Agency would also test interest on funding, financing, and procurement options, Bishop said.Tolls on the cardsBishop also told attendees the government was exploring tolling concessions to speed up road construction.All Roads of National Significance are being assessed for tolling.The concessions would mean the private company collects the revenue from a toll to offset its costs, while giving the government an up-front capital payment.The government would then re-invest that payment into other roading projects.It would also maintain ownership of the road built through toll concessions."We want to understand how we can grasp opportunities to use upfront capital to help fund future projects, like other countries do, unlocking economic growth and productivity benefits sooner," Bishop said.Speaking to media afterwards, Bishop said he would not get ahead of himself and announce a preferred option."The history of this stuff is politicians do a desktop study, it takes forever, it costs a lot of money, and then everyone gets excited about a particular option, and then they announce it without actually having talked to the private sector about what might be deliverable and how the financing and how the economics might stack up," he said."So we're doing that work first, before we start to firm up decisions about what we will build, how we will build it, and when we will build it."José Manuel Entrecanales, chief executive of Spanish firm Acciona, said he was "definitely" interested in getting involved.Acciona already has a presence in New Zealand through its work on the Puhoi to Warkworth highway, and the Eastern Busway.