Watch ITV Anglia's video report by Stuart Leithes
Passengers travelling on Great Northern and Network Rail on the Fen Line between Cambridge and King's Lynn got a taste of the new twice-longer eight-carriage service on Friday.
This was an early preview of a big change for passengers that will boost space and seats on trains from Sunday (13 December).
Great Northern is doubling the length of trains on this service from four to eight carriages - when its new winter timetable comes into effect.
Great Northern and Thameslink Managing Director Tom Moran said: "This long-awaited news will make a real difference for our passengers on the Fen Line between King's Lynn and Cambridge.
"I'm so impressed by the collaborative work we've seen between Great Northern, Network Rail and the communities along this route.
"By doubling the length of so many trains, we'll add 2,000 seats every morning which will make it easier for passengers to socially distance and, when people return after the pandemic, get a seat."
The upgrade to longer trains has required some changes to the infrastructure on the line which have been carried out by Network Rail with a grant of almost £30 million from the Department for Transport.
The upgrade has been welcomed by the Fen Line Users Association which campaigns for better services.
John Grant, chairman of the Fen Line Users Association (FLUA) said: "We welcome this major boost to Great Northern services for Fen Line passengers, which will help with social distancing now and relieve overcrowding when ridership gets back to normal. We are pleased that Waterbeach now has a half-hourly service and would like to congratulate Network Rail for completing the work on schedule despite the pandemic."
The longer trains will not just mean more seats for passengers - it will also make it much easier to adhere to to social distancing guidelines during journeys.
Rail Minister Chris Heaton-Harris said: "These improvements to the local rail network will provide better connectivity for passengers on this important commuter route."
"Longer trains will give passengers a better service, improving the network in a key part of the country as we continue to recover from the coronavirus pandemic."