South Korean researchers today will wrap up their inspection of a main railway line in North Korea, the Gyeongui line, and return home in the afternoon.
The inspection is part of a project by the two Koreas to eventually reconnect their rail networks.
Since last Friday, the researchers have checked 400 kilometers of tracks between the North Korean cities of Gaeseong and Sinuiju .
On Saturday, another team will cross the border for a survey of the North's eastern Donghae line.
The South Korean train cars used for the inspections will be moved to the city of Wonsan in the North, where they'll be linked up with locomotives and train cars belonging to the regime.
To do the inspections, South Korea had to bring resources into the North like oil.
And as for the security of those resources, Seoul has emphasized that the project is being carried out on a foundation of trust.
The joint survey is expected to be completed by December 17th.