In 1978 , the city planner discarded the proposal by Oslo Sporveier to build a new station at Slottsparken .
In 1978 , the city planner instead decided that Sentrum would become the interchange between the two systems .
In 1978 , the city planner discarded the proposal by Oslo Sporveier to build a new station at Slottsparken , and instead decided that Sentrum would become the interchange between the two systems .