The sister of a cyclist killed on a busy dual carriageway has backed the construction of £1.9 million new bus and cycle lanes, believing it will save lives.

Jo Walters, 28, was killed in Lewes Road, Brighton, in 2010 after swerving to avoid another cyclist on her way to the University of Sussex.

After her death, the family of the student launched a charity campaign to improve safety in the area, commissioning a report which showed the cycle lanes were too narrow.

The family’s protest helped convince bosses at Brighton and Hove City Council to build new cycle and bus lanes as part of a £6.2 million project to improve the area.

After the scheme went live last week – three months ahead of schedule – some drivers branded the new layout between The Amex stadium and the Vogue Gyratory “lethal”.

Others complained of congestion and long queues.

But during a heartfelt speech at the scheme’s official opening in Wild Park on Saturday, Ms Walters’ sister Lucy Johnston said she hoped the new routes would save lives.

She said: “While there is never going to be an upside of any kind arising from Jo’s death, it is really helpful for us to know that everyone who uses this cycle lane now is going to be so much safer.

“When we launched the campaign to improve the cycling infrastructure on the Lewes Road 18 months ago, I said to everyone in the room: ‘Jo was someone who just got on and did things – I really think that you should get on and do this.’ To their immense credit, the council and all other parties involved really did just get on with it.”

Members of the family joined dozens of people at the celebration event.

Among them was transport minister Norman Baker, council leader Jason Kitcat and Brighton Pavilion MP Caroline Lucas, who received a “backie” to the event as part of a mass bike ride to the park from The Level.

Councillor Ian Davey, chairman of the council’s transport committee, said the family’s campaign for change had been “crucial”. He said: “They were the catalyst for all this and I’m really confident some good will come from the tragedy of Jo’s accident.

“There’s rightly a discussion going on about what benefits the new layout will bring but the trust is supporting it because they are sure it will stop accidents and save lives.”