AN increase in traffic is causing more congestion on the M8 around Glasgow Airport, according to a confidential report.

Drivers trying to get to the airport on the only method of transport available are facing longer delays especially at peak times.

The Evening Times has seen the study carried out in to traffic volume on the motorway, which shows an extra 16,000 vehicles a day re using the stretch of the road to the west of Glasgow city centre.

Business leaders and Glasgow Airport said this proves what they had been witnessing and was further evidence that alternative methods of reaching the Airport are needed.

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The opening of the M74 extension through the south east of the city to the Kingston Bridge has led to the extra traffic from junction 22 at Kinning Park to junction 29 just after Glasgow Airport.

While the new road has been successful in taking some traffic away from the M8 in the east of the city and through the previously notorious bottleneck at Charing Cross it has has the consequence of adding to the problems in the west.

The report shows the extra traffic has led to queues of cars and lorries and longer journey times to and from the city centre to the Airport and to the Renfrewshire region.

Using the monitoring equipment on the motorway and traffic cameras Jacobs tracked traffic volume and flow between the interchange with the M73, eat of Glasgow through to St James interchange at Paisley, just after the Airport slip road and split it into five sub sections.

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The section with the biggest increase in congestion was the stretch west of the city to the Airport.

The report for Transport Scotland carried out by transport consultants Jacobs, stated: “There has been a constant and relatively significant increase in traffic levels between Junction 22 and Junction 29 from 2011 to 2017, which again is driven by the M74 Extension with the traffic attracted on to the M74 route re-joining the M8 along this section.

“This has led to a 22% increase in traffic levels on this section between 2008 and 2017, and is consistent with the equivalent decrease observed on the Glasgow East sub-section. This is likely to have had a noticeable impact on congestion.”

The data in the report shows that in the evening peak time vehicle speeds are reduced particularly around junction 26 to Hillington and Braehead.

The Jacobs Report showed said it provided some evidence average speeds have gradually reduced between 2014 and 2017 between 4pm and 7pm.

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The report concluded: “The data indicates that congestion has eased to the east where there has been a reduction in traffic, but increased to the west where traffic flow and journey times have shown increases.

Business leaders said the analysis confirms what they had experienced in recent years.

Stuart Patrick, chief executive of Glasgow Chamber of Commerce, said: “We had gradually notices increasing issues at peak times. We also had feedback form our colleagues in Renfrewshire that the overall sense of congestion was increasing and having an impact on surrounding streets.

This report seems to show that is in fact the case.

“The solution can’t be the re-allocation of road space or more roads. Rail is the most obvious route forward. This adds lustre to the argument that we need to reduce congestion to the airport.”

Mr Patrick said the report does show the success of the M74 project but forecasts for increased economic growth in Glasgow mean action on the M8 congestion around the airport was clearly needed.

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He added: “The M74 has had a positive impact at the other end of the city and clearly that investment has paid off. But we now have a challenge in the west and there is not an obvious road or motorway scheme that will address it.”

Glasgow Airport has been calling for action to address congestion.

Plans for a Glasgow Airport Access Project are included in the Glasgow City Deal but have stalled following concerns over the impact on the wider rail network.

A spokesman for Glasgow Airport said: “This confirms what we have known for some time and what we have experienced.and what people travelling to the airport and the wider Renfrewshire area for several years have told us. There needs to be a solution to address this.”

A spokesman for Transport Scotland said: “The M74 Completion Project opened to traffic in 2011 and has improved journey times and connections across Glasgow’s motorway network, particularly between South Lanarkshire and Renfrewshire and beyond.

“An increase in traffic on this part of the motorway was forecast during scheme development and as with all major infrastructure projects, we have been undertaking an evaluation of the performance of the project which will be published in due course.

“We are also currently considering how managed motorway solutions can help to improve the performance of the M8 and maximise best use of the existing transport infrastructure.”