The company has apologised for any inconvenience caused to bus users.
The work will cost £74,000 and gets underway next week.
The £14 million development has been approved and is expected to be completed in April 2022.
Drone shots show the scale of fenland flooding.
Councillors said it obscured vision for those pulling out at the junction.
The county council and contractors will be carrying out the work, and signs will be in place.
Industry officials say they are confident demand will recover after Covid and longer trains now are a step towards bigger future projects.
Drivers may have experienced delays due to the issue on the village road.
The expanded service will run under a new timetable starting this weekend.
An infrastructure review says the road would be a dual carriageway if it was being built now – but upgrading it will cost tens of millions of pounds.
The ward councillor visited the shelter last week to check it was suitable.
A councillor claims the authority's current stance breaches its own policies.
Eight carriages following completion of £29m upgrade to Fen Line
The mist could linger until lunchtime, say the Met Office.
Youtubers launch drone video of King's Lynn's fishing fleet.