The Renfrew Motorway is a four mile section of M8 that connects the Inner Ring Road south of Kingston Bridge with the Renfrew Bypass at Hillington. It was officially opened to traffic on 15th October 1976 having been constructed in two simultaneous contracts.
It features the widest section of motorway in Glasgow (and the second widest in the UK) at the large braided interchange at Plantation. Here, four carriageways with sixteen running lanes, handle traffic from three motorways in a very short distance. Today, the route handles over 100,000 vehicles a day.
M8 (J20 - 24)
M8 (J24 - 26)
Scott Wilson Kirkpatrick
1 and 2
Planning and Construction
As with many of the other Glasgow Motorway proposals of the 1960s and 1970s, the Renfrew Motorway was outlined in A Highway Plan for Glasgow published in 1965. Originally the scheme was named the “Scotland Street Motorway” but was later changed to match the naming convention of the other motorways radiating out from the Inner Ring Road.
The Renfrew Motorway was designed and constructed in two stages. Stage 1, from the Kingston Bridge to Helen Street, was designed by Scott Wilson Kirkpatrick & Partners and constructed by Balfour Beatty. Construction began on 17th September 1973, just weeks before all UK Government civil engineering contracts were placed on hold due to the oil crisis.
Stage 2, from Helen Street to the Hillington Interchange, was designed by W.A Fairhurst & Partners and constructed by Leonard Fairclough Ltd. Construction began on 8th January 1974. Holford and Associates were appointed as Consulting Architects as part of their contract with Glasgow Corporation.
Both stages opened to traffic at the same time on 15th of October 1976. The total cost of the scheme was £35 million, £20 million for Stage 1 and £15 million for Stage 2. That is almost £255 million today's prices.
Long sections of the Renfrew Motorway were constructed with four lanes in each direction. This was required as traffic projections indicated that it was likely to attract more than 100,000 vehicles per day when surrounding motorways and expressways were completed.
The motorway corridor was selected fairly easily with large amounts of adjacent sub standard housing due to be demolished. The corridor also ran parallel with the main railway line between Glasgow and Paisley reducing community severance issues. The majority of the route was constructed at ground level or in cutting with the only elevated section being Scotland Street Viaduct.
Paisley Road West, Helen Street and Dumbreck Road were each slightly realigned and carried over the new motorway on overbridges. Several footbridges and underpasses were provided to ensure people could still access areas on either side of the route. Another key aspect of the design was to provide a route that was as aesthetically appealing as possible and have as minimal an impact on the local community as possible.
Footbridges were provided at regular intervals to ensure pedestrians weren't disrupted by the construction of the new motorway. A key feature of those constructed on Stage 1 are spiral approach ramps with landscaped areas in the centre.
One of the most interesting engineering challenges of the Renfrew Motorway came from the task of working alongside and above a busy electrified railway line. The railway was operational for most of the day meaning that work had to be undertaken late at night when it was closed. This was a fairly unusual practice at the time.
The route has a number of railway structures, the most impressive of which is the Craigton Rail Bridge. This well designed structure combines a pedestrian underpass with a road above and the railway below. The construction of the motorway also required extensive service and utility diversions (specifically gas, water, telephone and electricity services) in advance of the main works. A new sewer was also built in a tunnel to collect surface water and deposit it in the River Clyde
Holford and Associates completed photo surveys of the proposed route corridor for the motorway in late 1966. In this image, taken at Berryknowes Road, it can be seen that site clearance had already started.
The M8, M74 and M77 and a number of local routes converge on this incredibly wide and crowded road space which is only around 1 mile long. With sixteen traffic lanes spread across four carriageways, this is the busiest section of the Glasgow motorway network. At junction 22 the design is that of a two-level, twin-forked, single directional interchange which links both the inner and outer carriageways. Since 2007, a U-turn loop beneath Scotland Street viaduct provides a link for M77 northbound to M8 westbound traffic.
The design of this exceptional stretch of urban motorway had its origins in The Highway Plan. The use of multiple carriageways was required to cater for both traffic from the west and south flanks of the Inner Ring Road whilst also handling traffic from the Ayr Motorway (M77). The use of braided carriageways is a common feature of North American urban freeways.
The braided carriageways of Plantation Interchange have a considerable footprint. Construction works in this area were on a very large scale and posed several engineering challenges. Works took three years to complete.
It was initially intended that only the inner carriageways would be constructed as part of the main Renfrew Motorway contract, with limited advanced works for the outer section. Construction of the outer carriageways would follow later as part of the construction of the South Flank of the Inner Ring Road.
A few months prior to construction, the Scottish Development Department made additional budget available to Glasgow Corporation (said to be due to the inability of Edinburgh’s roads department to get their proposals off the ground) and the outer carriageways were included within the main contract. In hindsight this was an excellent decision as they now cater for M74 traffic joining and leaving the M8.
For five years the curved, south facing ramps at junction 22 were unused. This changed in August 1981 with the completion of the Dumbreck Road Connection section of the M77.
Modifications were made to this stretch with the completion of the Seaward Street Loop and the M74 Completion schemes. The loop involved the construction of a narrow slip road for cars and lights vehicles enabling them to travel from the northbound M77 to the westbound M8 without having to join the roundabout beneath Scotland Street viaduct. This was constructed as a way of reducing traffic in the Dumbreck area of the city. It opened in 2007, was designed by Glasgow City Council and built by Luddon Construction.
In 2011, the Renfrew Motorway was connected to the M74 Completion scheme. In advance the outer carriageways were widened from three to four lanes running lanes. This was accomplished by removing hard shoulders.
This aerial photo, taken in the autumn of 1976, illustrates clearly the scale of Renfrew Motorway around Plantation. It is the second widest section of motorway in the UK with sixteen traffic lanes spread across four carriageways.
Renfrew Motorway Features
East of junction 23, and in advance of the completion of the M74 scheme, a permanent barrier, similar to that on the Kingston Bridge, was erected on the westbound carriageway. This was installed to improve safety, traffic flow and reduce weaving in anticipation of the increased traffic flows to and from the new motorway. The barrier segregates lanes 1 and 2 from lanes 3 and 4. Lanes 1 and 2 are accessed from the M74 and outer carriageways at Plantation while lanes 3 and 4 come from the M8 and Kingston Bridge. M8 traffic can no longer leave the motorway at the Ibrox junction and is encouraged to use junction 24 at Helen Street.
Access to the Clyde Tunnel south approach road is provided at junction 25. The design is a trumpet-dumbell hybrid with free flow elements on both sides of the interchange which also incorporates a roundabout. The roundabout is a recent addition having been added following the construction of a nearby industrial estate in the late 1990s.
Junction 25 was also intended as an interchange with the South Link Motorway. This motorway was intended to cater for traffic through the south of the city and provide access to the westbound M8 from the M77 Ayr Motorway. By the time Renfrew Motorway was completed the planned route had been reduced to expressway standard due to complaints from local residents, however an allowance was made for the future connection within the Stage 2 design. Wide verges and areas of unused carriageway remain on the ground today.
At Cardonald, an interchange was provided to allow for easy access to the Clyde Tunnel via its south approach road. Significant changes were required at Berryknowes Road and Cardonald Railway Station was completely rebuilt to accommodate the new motorway.
Junction 25a was completed in advance of the Braehead Shopping Centre complex opening in 1998. The junction has east facing slips only with a fork type design allowing a free flow movement to the M8 and providing relief to Hillington Interchange just slightly to the west.
Traffic using the spur passes beneath the M8 via a short underpass. While the junction was constructed in 1999, this underpass was in place when the Renfrew Motorway opened in 1976 having once been a bridge over a railway line that served the Kingsinch Dockyards. The Greater Glasgow Transportation Study proposed that the planned Erskine Expressway would have passed through here. The Expressway would have followed the same line as the current spur and then continued westwards to the north of Renfrew and on to Erskine.
The spur, which is the only unnumbered M8 spur of recognisable length, lacks a central reservation barrier at its northern end despite being under motorway regulations. Design work was by Dougall Baillie Associates and the main contractor on the scheme was Balfour Beatty. In addition to the construction of new slip roads, a section of the M8 was widened to five lanes and additional sign gantries were installed.
From the Archive
Scott Wilson Kirkpatrick and Balfour Beatty commissioned a film to chart the construction of Stage 1 of the Renfrew Motorway. The film, produced by Oscar Marzaroli's Ogam Films, was released in late 1976.
A copy of the film was donated to the Glasgow Motorway Archive in 2019 and we are delighted to present it here. With thanks to AECOM, successor company of SWK.
This article was first published in November 2020. Updated October 2022.