INVESTIGATIONS are continuing into the cause of a 'sinkhole' which has opened up in Broad Street.

More than 24 hours after it was discovered, frustrated commuters were left none the wiser as to how and why the gap in the road surface, next to Boswells, has appeared.

UPDATE: Sinkhole caused by 'mud-filled medieval ditch'

Workers from Oxford City Council were erecting new fencing around the hole this morning, in preparation for a digger arriving on site.

But it is still not known what caused the road to collapse. 

Oxford Mail:

Oxford Bus Company, whose carefully planned diversions in place for St Giles' Fair were scuppered by the problem, has said it shows the 'fragility of bus routes in the city'.

The 300 and 500, which had to be split yesterday, have now returned to their normal routes after the end of the fair, which is relieving pressure on the network. 

Stagecoach and Oxford Bus Company have both said their services are all running normally. 

Oxford Mail:

Phil Southall, managing director of the bus company, said: "This demonstrates how fragile bus routes in the city are if one route becomes blocked through unforeseen events like this.

"It causes widespread disruption and inconveniences our customers massively.

"Cross city routes 300 and 500 have been seriously affected and part of our sightseeing tour for visitors has had to be cut."

Mr Southall said the problems showed the importance of keeping Queen Street open to buses.

The county and city councils have long wished to pedestrianise this road but their request was turned down by the Government last year.

Mr Southall added: "It further highlights how vital it is for Queen Street to remain open to buses.

"It would enable bus operators to keep options open in case similar incidents happen in other Oxford streets where our options to divert are heavily limited and impact the day to day activities of residents and visitors.

"Our operations team have done a great job re-routing services quickly and we ask customers to check our website, social media channels and the media for live updates."

Oxford Mail:

Oxford's other major bus company, Stagecoach, were also forced to put diversions in place and installed information boards in the city centre to direct passengers to the correct stop.

Spokeswoman Tracey Warmington said: "We are working to run these services as reliably as we can under the temporary circumstances."

The incident is the second time this year that a hole in the road has caused major issues in Broad Street.

In January the road was shut for almost a week due to a similar problem.

Oxford Mail:

On that occasion the historical importance of the area and 'complex nature' of the job led to delays in repairs to a leaky water pipe.

Spokesman for Oxford City Council Tony Ecclestone said: "Oxford Direct Services, on behalf of the County Council, and Thames Water, are urgently investigating a sinkhole that appeared in Broad Street.

"We will issue a further update once we know more about the cause."

Abby Turner, spokeswoman for Thames Water, merely said: "We’re assisting the council with their investigations."