The solar-powered sign, which will alert drivers if they are exceeding the speed limit, will start off on Dirleton Avenue, where police and community leaders agree the problem is greatest.
The sign will include data logging, meaning it will store information on the number of drivers speeding, and was partly funded by a £1,000 grant from the East Lothian Community Safety Forum.
North Berwick Community Council had previously hoped to secure money from the Community Environmental Fund but was told that the project did not qualify.
However, at the community council's meeting last Tuesday, group chair Pat Burton explained that funding had been secured and thanked Councillor Stuart MacKinnon, North Berwick Coastal ward member, for his efforts.
Mr MacKinnon, she said, had gone to talk to his East Lothian Council administration colleague Councillor Stuart Currie, who chairs the Community Safety Forum, and had been able to secure the grant.
"I'm very, very grateful to Stuart MacKinnon," said Mrs Burton.
Kathryn Smith, the community council's secretary, revealed that Colin Baird from the local authority's road safety department had emailed her asking for a first location for the sign, together with others where it could go in the future.
He had added in the email that he hoped to have the sign up and running by the middle of March.
PC Jim McLeod, police representative at the meeting, said the western approach to North Berwick, on Dirleton Road and Dirleton Avenue would make the most sense as the starting point.
"With the volume of traffic coming in, I think that would be No 1," he said.
There was general agreementn, while there was debate as to whether it would be best to have the sign just inside the 40 or the 30-mph speed limit.
The 30 limit was the one settled on, community councillor Jim Goodfellow saying: "Just inside the 30 is where it's dangerous. The roads narrow and there are children crossing there."
He also suggesting positioning the sign so that it could function for traffic travelling in both directions, as he had heard more complaints about people speeding on their way out of the town than coming in.
Several other locations for the future were also suggested. North Berwick Coastal ward councillor David Berry suggested Lochbridge Road, as "the residents have repeatedly expressed concerns over traffic speeding there".
Mrs Burton, meanwhile, noted that there were frequently cars speeding on Dunbar Road coming into the town from the east and that the "beauty" of the set-up was that the sign could be moved around.
Community councillor Ian Watson also mentioned that a meeting of Lime Grove Tenants' and Residents' Association had revealed "quite a lot of concern about cars speeding into North Berwick from Tantallon Road and not slowing down until they hit the roundabout at Tesco".
"They're also doing the same coming out," he added.
"A lot of cars after the roundabout just fire themselves out of North Berwick. A lot of cars coming out of Lime Grove have said there have been several near misses with cars coming out of North Berwick and just putting their foot down."