A damning report by highways chiefs has identified the “severe” impact a 750-home development will have on traffic if steps are not taken - prompting a recommendation to refuse the current plan.

Developers at Quinn Estates want to build the so-called Large Burton estate on fields off Willesborough Road in Kennington and have submitted an outline application to Ashford Borough Council.

Company bosses say they are proposing a "comprehensive package of mitigation" to improve the road network - but Kent County Council’s highways and transportation division has highlighted its concerns with parking, road capacity and the applicant’s queue forecasts.

The authority’s principal transport and development planner Matt Hogben says the scheme - officially called Conningbrook Park and proposed for fields opposite the existing Little Burton estate - will have a big impact on the road network if mitigation is not implemented.

Mr Hogben wrote: “The proposals will result in ‘severe’ capacity issues at the William Harvey Hospital roundabout and along the A28 corridor between the Conningbrook roundabout and the junction of Simone Weil Avenue and Canterbury Road, with no mitigation schemes currently being agreed with the local highway authority to address these capacity issues.”

The traffic authority’s analysis has found it currently takes four minutes and 55 seconds to drive from the Conningbrook roundabout to the signalled junction between Magazine Road and the A28 Canterbury Road during the morning rush hour.

In the afternoon, it currently takes three minutes and 54 seconds.

But by 2030, the KCC model predicts the journey time in the mornings will increase to 36 minutes and seven seconds if the Large Burton development - along with other schemes which have already been approved - is built.

In the afternoon, the estimated journey time shoots up to 11 minutes and 11 seconds.

The report adds: “The 2030 ‘with development’ model demonstrates the route falls apart once the development is added to the model.

“Mitigation is therefore required along the corridor otherwise the proposals will result in a ‘severe’ capacity issue.”

Quinn Estates says it has worked in Ashford "for many years" and understands that the development's impact on traffic is the "main concern" for people living in the area.

But the report also raises concerns over the area towards Junction 10, saying: “KCC has concerns the William Harvey Hospital roundabout has not been currently modelled correctly by the applicant.

“The operation of this roundabout is hampered at certain times of the peak hour period.

“The [Quinn Estates] model does currently not replicate this as it assumes a balanced flow across the peak period.”

Despite Quinn Estates announcing its intention in July to go through with the estate plan, KCC also highlighted a lack of consultation from the developers before the plan was submitted.

It said: “Unfortunately KCC highways and transportation did not have any pre-application discussions with the applicant regarding the proposed site layout for the detailed element of the site and there are a number of fundamental concerns with the application as currently submitted.”

Ultimately, in its current state, the traffic officer recommends the refusal of the scheme, citing that “the proposals do not conform to the agreed [planning authority] standards and do not, therefore, meet the guidelines in respect of highway safety, convenience and sustainability".

'The proposals do not conform to the agreed standards...' - Kent Highways

The report also raises fears over parking, saying: “The proposals do not provide adequate vehicle parking facilities in terms of allocated visitor parking and parking for the community centre within the site and this is likely to lead to vehicles being parked on the highway, to the detriment of highway safety.”

Responding to the recommendation, Quinn Estates says it has been in talks with KCC.

In a statement, the company said: "We have been in discussion with KCC Highways since 2017 regarding the transport assessment, trip rates, site access points and the extent of the submitted model and we are pleased to see that many aspects of our submission are acceptable to the highway authority.

"We have met with the local community on a number of occasions and are well aware that traffic is the main concern for people who live in the area.

"We have worked in Ashford for many years and understand these concerns.

"As such, we are proposing a comprehensive package of mitigation to ensure the development delivers betterment in the future case to the local highway network.

"Our proposal delivers in excess of £4 million of off-site highway improvements to mitigate the impact of the development, these measures are set out in the application transport assessment.

"The transport assessment shows that without our development, by 2030 journey times on the A28 will have increased from four minutes 55 seconds to 18 minutes 34 seconds in the morning peak, and three minutes 54 seconds to eight minutes 48 seconds in the afternoon peak.

"Therefore, mitigation is required even if our development did not come forward."

Quinn Estates has listed the "extensive mitigation" it proposes, including:

• "Substantial contributions towards junction 10a"
• "Significant improvements to the Simone Weil junction works on the A28 corridor"
• "Improvements to the William Harvey Hospital roundabout"
• "Funding of bus services to and from the town centre service"
• "Funding towards new pedestrian route over the ‘hump back bridge’ and a new toucan crossing over the A2070"
• "Funding towards a new bridge to country park over the railway line"

The spokesman added: "This comprehensive package of works will ensure that when compared to the situation in 2030 without the development and associated mitigation the savings are substantial – over 13 minutes in the morning peak and circa five minutes in the afternoon peak.

"As such, the assertion that the development will cause gridlock is entirely incorrect.

"Without the substantial funding and investment in improvements we will provide as part of this development it is clear from our assessment that there would be significant congestion and gridlock in Ashford that would not be resolved."

The spokesman added that the findings in the KCC transport assessment are "quite normal".

"They’ll work with us before the plan comes in," he said.

“They point out which things need resolving, the report informs us of what we’ll need to do - probably in the next couple of weeks - to avoid its refusal.

"They raise the points that need to be looked into.

'Without the substantial funding and investment in improvements we will provide as part of this development it is clear from our assessment that there would be significant congestion and gridlock in Ashford that would not be resolved...' - Quinn Estates

“We work with KCC, and you normally have a stage one road safety audit and consultation but you don’t do that without finalising the plan first, so we’ve got to finalise it first.

“We’ll look at the points raised with our traffic consultants, but we’re content that we can overcome any issues raised by KCC.”

Quinn Estates has submitted a hybrid application to Ashford Borough Council, asking for outline planning permission for up to 430 homes and full planning permission for 320.

The 81.9-acre agricultural site has been earmarked for development under the council’s Local Plan.

As well as the homes, a primary school, gym and community centre are also planned for the land.

To view the Conningbrook Park scheme - which also features open parkland next to the railway line - visit www.ashford.gov.uk and search for the 19/00025/AS application.