The subway underneath the train station is a main route for commuters and revellers heading from Reading town centre to Caversham Road and the Reading Festival site in Richfield Avenue.
The council undertook an emergency closure to remove unstable roof panels and hanging netting overnight from 8pm to 6am today (Thursday, August 24).
The issue was first raised by then-Conservative councillor Harry Kretchmer last July, who called the state of the subway “truly awful.”
Mr Kretchmer retired from the council ahead of the local elections this year.
The council’s Labour administration has been criticised by the Conservatives for not working on the subway roofing sooner.
Councillor Clarence Mitchell (Conservatives, Emmer Green), the leader of the Conservative Group on the council, said: “Reading’s Conservative Councillors first raised the appalling state of the station underpass roof with its holes and loose netting more than a year ago and we then supported the approval of more than £200,000 in urgent repair work at a policy committee last December.
“Yet Reading’s Labour administration has only now been forced to act urgently because of Network Rail’s security concerns on the very eve of the Festival when tens of thousands of young people are already beginning to pass through the station.
“As we argued last year, this repair work should have been completed months ago and not be forced to happen now because of Network Rail’s urgent concerns.
“The Labour administration has once again been caught out, saying it always puts improvements to Reading’s infrastructure first but then failing to deliver them where and when they are most needed.”
The station subway reopened as scheduled at 6am.
A spokesperson for Reading Borough Council said: “The council acted swiftly and decisively to take action on security concerns ahead of the Reading Festival, at the request of Network Rail that they only raised on Monday evening.
“The additional and substantial work to refurbish the subway and make it accessible for cyclists as well, is in plans to begin in the upcoming weeks after the intense foot traffic of the Festival is cleared.”
The council’s policy committee approved a spend of £205,761.05 to make improvements to the subway to allow cyclists to pass through the subway on their bikes at a meeting on December 15, 2022.
The subway is currently designated for pedestrian use only.
Cyclists area meant to dismount and push their bikes through the passage, but some have been observed cycling through in the past.