With reporting by Dries Arnolds and Janene Pieters

A team of about 40 journalists and technicians rode the new Amsterdam Noord-Zuid subway line on Thursday morning, in the first full-scale test run of the route. The subway reached its top speed of about 80 kilometers per hour, taking the observers from Amsterdam Centraal to Amsterdam Zuid, then back north to the final stop at Amsterdam Noord.

The entire trip occurred without a hitch, with the travellers then brought safely back to Amsterdam Centraal to end the historic journey. The ride began at 8:48 a.m., arrived at Zuid at 8:54 a.m., wound up at Noord by 9:26 a.m. before concluding at central station at 9:33 a.m.

The line, which was initially set to open in 2011, will start operating on July 22nd next year, alderman Pieter Litjens said at the test run. Journalists were brought along despite being 15 months away from the public unveiling because "it's good to inform people of what we're doing", Litjens told the NL Times.

The construction and heavy concrete work on the subway line that connects Amsterdam Noord to central station, Dam Square, the RAI convention center and the World Trade Center finished several months ago. The coming months will involve substantial safety, security and IT testing. "We want to have the safest subway system in the world", Litjens said.

Technicians are currently testing the integration of all systems, including fire, safety, rescue, elevators and IT, Emiel Vergouw explained, Test Manager for the Noord-Zuid Line . "We're constantly learning more and more as we go forward." According to him, advice from other subways around the world was invaluable, especially from London. "London is nearby, very complex and they just built a new line."

The journalists and technicians traveled the entire line, with driver Vlastimir Medica driving the subway train. It was a strange experience for him, Medica told NL Times. "Normally I'm alone here in the cabin, and today there are many people with me!", he said, adding that he is really happy to be part of the testing.

"I get to be the first one in here!" exclaimed Medica, who has experience driving all metro routes in Amsterdam.

Amsterdam plans to invest more in its subway infrastructure and improvements to public transit in the city. The city is currently investigating an east to west subway line, which would carry a high cost of around 7 billion euros, Litjens noted. They are also looking into two light rails, one connecting Zuidas to Schiphol and one connecting Amsterdam West to Sloterdijk.

One of the biggest problems that he will face is convincing the public that this is the right direction for the city, as years of delays and billions of euros in cost overruns plagued the construction of the Noord-Zuidlijn. The initial budget for the subway line was nearly two billion euros less than the final projected cost.

Nevertheless, Amsterdam ultimately wants 40 to 50 percent of commuters in the city to use public transit, though Litjens admitted that the city still has "a long way to go" to achieve that goal. Before any new subway or light rail routes are constructed, city hall also has to convince the national government that there is a business case for the infrastructure project.

Construction on the Noord-Zuid line was anything but smooth. It began in April 2003 with an estimated completion date of 2011. Problems with construction under central station and further south at the Vijzelgracht were the cause of many delays, as the cost of construction ballooned.

In August 2015 the bankruptcy of key contractor Imtech raised concerns about the construction of elevators, escalators, lighting, and the electrical installations that power the railway and air ducts. There were fears that this, and the bankruptcy of metal construction firm Oskomera would cause further delays, despite alderman Pieter Litjens' assurances to the contrary. Contractor Visser and Smit took over Imtech's work, while key Imtech personnel were retained after the bankruptcy to reduce the possibility of any new learning curves.

Further fears of delays were caused in September 2015, when director of the project Pieter Dijk announced his resignation.

After all these delays, the completion date was set to be in October 2017. But in July 2016 alderman Litjens announced a further delay, setting the completion date at July 2018. This delay was largely attributed to problems resulting from the Imtech and Oskomera bankruptcies, Litjens said on Thursday.

When construction was approved in 2002, the budget estimated the total cost to be in the region of 1.4 billion euros with a contribution from the City of Amsterdam of 317 million euros. The current price tag is 3.1 billion euros with the contribution for the city standing at more than five times the original estimate.