National Highways said it has made changes to roadworks at Botley Interchange to try to prevent a repeat of the miles of tailbacks yesterday.

Additional measures include further signage further afield and as far away as the M4 and M40 to highlight the temporary road layout and that delays are expected in the area.

There are also extra permanent road markings to reinforce lane discipline on the approach to the interchange and permanent traffic lights will covered and be replaced with manual lights which will be remote-operated to keep the roundabout and arms flowing.

Box junctions will be re painted to keep the junction clear at the end of the A34 SB exit slip and extra diversion routes are being examined to disperse traffic to other suitable routes.

National Highways said this is ongoing as they need to be discussed and agreed in partnership with Oxfordshire County Council.

Thames Valley Police was called in to manage the chaos yesterday after improvement works to the structure of the bridges caused gridlock on the A420 and A34.

One motorist Fiona Pocock left Kingston Bagpuize at 7.45am and did not arrive at the Seacourt Park and Ride in Botley until 12.37pm.

Oxfordshire County Council said two narrow lanes were due to stay open over the roundabout instead of the closure of one lane.

Highways councillor Andrew Gant said he thought there were now too many signs in various  places, including works on Botley Interchange which were causing confusion for drivers.

"This is planned work," he told Radio Oxford. "What was supposed to happen in terms of mitigation had been planned and had been agreed. 

"To be sure there's a question mark about the level of communication.

"Sign fatigue is settling in. There's so many of the bloomin' things."

Mr Gant also said representations would be made to National Highways "in the strongest possible terms".

National Highways apologised again for the disruption.

A spokesperson said: "We apologise for the congestion around Botley Interchange and we are taking additional measures to minimise disruption while this vital maintenance work takes place.

"The barriers at the roundabout above the A34 need to replaced. To protect those working on the scheme and ensure the safety of those travelling close by it has been necessary to put concrete barriers which reduces capacity for short section of carriageway over the A34 on both bridges.

"We do all we can to avoid disruption and to raise awareness of our plans we sent around 7,000 letters to local residents and businesses. We also have over 400 signs in place. These warn of delays and a new temporary road layout as far away as the M4 and M40, with many of these in place for over a month.

"We are continuing to look into any further measures we can take, but would continue to ask people to allow additional time to complete their journeys if they need to travel through this section of road."