The Queen and the Duke of Edinburgh are among the very first to travel on one of the new high speed Hitachi trains being built for the region.
It was a milestone for the massive project to upgrade the Great Western network.
The scheme aimed at easing some of the worst crowding in the country remains late and over budget.
But the new trains will start to enter service later in the year.
They will eventually run from Paddington to Reading, Newbury, Didcot, Bedwyn, Swindon, Bath, Bristol and through to Wales and Devon and Cornwall.
Our Transport Correspondent MIke Pearse has been talking to commuters who say the improvements can't come soon enough.
Mike spoke to Paul Gentleman from Great Western Railway and Chris Irwin from Travelwatch South West.
It's the first regular train service to link Wareham with Swanage, in Dorset, in 45 years.
Civic dignitaries joined rail enthusiasts today for the launch of the new service which marks the the culmination of years of campaigning and hard work.
Much of the branch line was torn up after British Rail closed the route in 1972 but it has gradually been rebuilt and improved and now represents an amazing dream come true.
As Richard Slee reports.
Richard spoke to Peter Sills, Colin Stone and Peter Frost, all railway volunteers. He also spoke to Director of Project Wareham Mark Woolley.
Southern is understood to have called an urgent meeting with the train drivers' union Aslef this afternoon in a desperate attempt to try to avert next week's industrial action. Up to 600 trains a day would be cancelled.
Around 1,000 drivers are set to start an indefinite overtime ban on Sunday.
The company is refusing to confirm the peace talks, but union sources say there has been contact with them.
Services will be in chaos for hundreds of thousands of passengers if the action goes ahead.
It is understood both sides will meet at lunchtime.
So far months of talks have failed to reach agreement over driver-only trains.
“After over five months of intense negotiations and two peace deals agreed and recommended by the ASLEF executive, we are dismayed the union leadership is taking this action, which is designed to impact as many of our passengers as possible.
“Driver-controlled operation with on-board supervisors was fully implemented back in January and thanks to this we are running more trains than before and our service has improved for five consecutive months. We’re safely running over 80,000 trains a month with drivers controlling the doors across our network – we’re sorry that passengers will suffer as a result of this unnecessary action.
“We have worked our hardest to resolve this dispute with ASLEF. If this action does go ahead we will run as full a timetable as possible. We will be working around the clock to evaluate the impact and develop contingency plans which will be advertised as soon as possible.”
Rail users who travel by Southern could be in for more disruption. Train drivers belonging to the ASLEF union are to start an overtime ban.Read the full story ›
Delays of up to ten minutes on Chiltern Railways between Haddenham and Thame Parkway and Banbury due to road vehicle hitting a bridge at Bicester North. Source:Train Operating Company.
Train services have been suspended on CrossCountry and South West Trains between Eastleigh and Basingstoke after an incident.
Trains are unable to run on any of the lines between the two stations.
CrossCountry tickets are being accepted on Chiltern and Great Western Railway services.
South West Trains tickets ares being accepted on CrossCountry and Great Western Railway services.
Thousands of rail passengers in the Thames Valley appear to have heeded the warning about disruptive engineering works and stayed at home.
This was the 07.08 Newbury to Ealing Broadway train this morning with hardly any passengers. It is normally one of the busiest in the Thames Valley with standing room only.
Some carriages are deserted. Trains will only go as far as Ealing Broadway until Friday because London Paddington remains closed for Crossrail work.
Some rail passengers travelling from the Thames Valley to London gave their reaction to the rail disruption over the festive season. London Paddington is closed - trains are terminating at Ealing Broadway.
The head of Network Rail has justified the closure of major mainline railway stations such as London Paddington and Waterloo over the Christmas holidays this year.
The firm's Chief Executive Mark Carne said he was sure passengers would understand that this is the quietest time of year on the rails.