Work to build a safety barrier on the stretch of Oxford's Eastern Bypass where four young people lost their lives was due to finish today.

The £600,000 concrete structure on the A4142, between Kiln Lane and Horspath Driftway, has been built by Oxfordshire County Council.

County Hall bowed to public pressure following a crash in May last year, when three schoolboys and a student died after a car crossed the central reservation and collided with oncoming traffic.

Marshall Haynes, Josh Bartlett and Liam Hastings, all 13, and from Oxford, and Howard Hillsdon, 21, from Yarnton, died in the accident, prompting calls from the victims' relatives for safety measures on the road.

Earlier this month, Angela Dublin, 45, of London Road, Headington, admitted four charges of causing death by dangerous driving. She is due to be sentenced next week.

David Robertson, the council's cabinet member for transport, said: "I'm pleased the barrier is now in place and the risk of crossover accidents has been substantially reduced, following the horrific incident last year.

"The highways department, which designed and installed the barrier, has worked hard to ensure that it's built within the allocated time and budget."

A 50mph limit on the whole stretch of the Eastern bypass will come into force on Friday.

The speed restriction is being introduced because the bypass has a higher than average number of accidents for its type of road, said Mr Robertson. He added: "It should reduce the number of accidents of all types."

The completion of the work comes just before the unveiling of a memorial to Mr Hillsdon, an Oxford Brookes University student.

A tree, donated by Oak Tree Nurseries, in Witney, will be planted at William Fletcher Primary School, in Yarnton.

Earlier this month, his parents Graham and Julie opened a memorial garden at Spirit Health Club, at the Pear Tree Holiday Inn, in Oxford, where their son used to work.

Plans for two roadside memorials to the children and Mr Hillsdon, are also under way, but the details are being finalised with relatives, said Mr Robinson.

The children who died were all travelling to the birthday celebrations of 13-year-old Anton Dublin in a Citroen Xsara driven by his mother.

Four more children in the same vehicle needed lengthy hospital treatment for their injuries.