Glasgow Airport Interchange

This article is about the junction at Glasgow Airport.
For other Airport junctions, see Airport Roundabout.

Glasgow Airport Interchange is junction 28 (formerly junction 9) of the M8. Although originally built as a Trumpet Interchange, it has been heavily modified over the years as both the airport and surrounding road network have developed. The east facing slips of the original layout survive almost untouched, the onslip being a simple straight run from the roundabout onto the motorway, while the offslip is looped round inside the westbound onslip in the opposite corner. These sliproads now meet an additional roundabout on the south side of the motorway, on Sanderling Road, which serves a business park area home to many of the businesses that inevitably spring up close to airports, including offices, hotels and car parks. The eastbound offslip has, however, been completely rebuilt and now curves round to feed directly into the Airport's one-way system, looping around a car park and past the drop-off point to reach the roundabout. Although this is highly beneficial for traffic destined for the airport, it is somewhat awkward for the small amount of traffic heading for other destinations. This roundabout is, furthermore, a teardrop shape creating a semi- dogbone layout under the motorway, although this only really affects traffic that has missed a turning on the Airport loop.

Due to the addition of Junction 28a, providing a direct link to the A737, a short distance to the west, the west facing slips for J28 no longer connect directly to the motorway. Instead they run parallel to the roundabout at Junction 29, where they feed into that junctions east-facing slips. This removed the dangers of weaving on the motorway between the junctions, and with two lanes in either direction, these extended slip roads rarely seem to suffer from congestion.

History

The original Trumpet layout

The junction was originally built as a Trumpet layout only serving Glasgow Airport to the north. There was no connection to the Gockston area to the south, which at the time was a large estate of post war prefabs which were in the process of being replaced with more permanent housing. The roundabout on the north side of the motorway was originally a standard roundabout, connecting all four sliproads. The original eastbound offslip can still be seen as an overgrown strip of tarmac between the motorway and car hire premises.

The opening of Junction 28a, providing a direct link to the A737 changed the west facing slip roads to go via the roundabout at Junction 29. It was probably at this time that the sliproad into the airport was redirected to its current line.

Routes

Route	To	Notes
M8	Glasgow, Edinburgh, Renfrew (A741)
M8	Greenock, Linwood, Erskine Bridge (M898)	indirectly accessed from J28 via Junction 29
	Airport Terminal Building, Airport Services, Drop Off/Pick Up Car Park, Car Park 1, Car Park 2	St Andrews Drive West
	Car Park 3, Long Stay Car Park, Admin Building, Cargo Terminal, Services, Business Aviation Centre	St Andrews Drive
	M8, Greenock, Linwood, Erskine Bridge (M898)	Sanderling Parkway to Junction 29
	Paisley, Renfrew, Cargo Terminal, Long Stay Parking	Sanderling Road
M8	Greenock, Linwood (A740), Erskine Bridge (M898)
A8(M)	Greenock, Paisley, Erskine ferry (A726)
A8(M)	Glasgow, Edinburgh, Renfrew (A741)