DO YOU KNOW THE PURPOSE OF THESE BRIGG BOLLARDS?

Can anyone remember the purpose of these Brigg bollards?
They appeared in the early or mid-1990s at the time the inner relief road was constructed and pedestrianisation was introduced.
This was still the era of Humberside County Council and Glanford Borough Council - before the creation of the North Lincolnshire unitary authority.
Tall brick walls were built on both sides of the diverted A18. But rather than continue one of them as far as the fire station, a long line of metal bollards was added instead at the very end of Grammar School Road South.
Were they semi-permanent and capable of being removed if it was decided after all to allow cars to join the A18 from Grammar School Road South but not to enter Grammar School Road South from the main road?
Such a one-way flow would certainly have helped reduce traffic along Queen Street, Bigby Street and the Monument roundabout.
Perhaps the authorities decided to see how Plan A worked out and were then happy with the new road layouts and traffic flows that had been created in the 1990s.
Therefore, it was unnecessary to consider establishing a direct (one way) link between Grammar School Road South and the A18.
Or perhaps that theory is just a load of bollards! Can you recall the reason why they were put up?