The frequency of the service will be increased to seven daily round trips starting 2 April, when the second of the four-phased test starts.
The third phase will see the introduction of a daily service between Riyadh and Hail and all four day trains operating between the two routes.
The final test phase, commencing in 2018, involves the introduction of two passenger night trains serving the entire 1,418km route, which has six stations. The stations are located in Qurayyat, Al-Jouf, Hail, Al-Qassim, Maajma and Riyadh.
On the initial test phase, the trip originates in Riyadh at 10:00am and runs north to Al-Qassim for a duration of two hours and 31 minutes. The return trip leaves Qassim at 3:00pm. Tickets are sold for SR40 ($10.7) for adults and SR20 for children, according to local media reports.
Spains CAF won the $53m contract to supply five diesel-electric locomotives for the North-South Railway. The day trains have a top speed of 200 kilometres per hour (kph) and the capacity to seat 444 passengers. The night trains top speed is 160kph with a capacity to seat 377 passengers.
The line is planned to link with the Al-Haditha land port close to the border with Jordan and with the Dammam-Riyadh line, Saudi Arabias first passenger line that came into service in 1951.
Serco Group, Network Rail Consulting and Freightliner Group, all of the UK, won the five-year, $185m contract to operate the line.