Major roadworks on the M74 through South Lanarkshire have been extended by two months.
The bridge refurbishment project at Nethan Viaduct, between junctions nine and 11 of the motorway, has been affected by “recent adverse weather [which] has impacted hydro-demolition of the concrete and delayed progress”.
It means the current set-up of two traffic lanes in each direction with speed cameras enforcing a reduced 30mph speed limit is now scheduled to remain in place until the end of June, rather than the original planned completion date of April 30.
The current phase-one work, taking place on the hard shoulder and inside lane of the northbound carriageway, was due to be completed earlier this month but is now programmed to take until February 2.
Additional resurfacing has also been carried out on the same section during this period; which will now be followed by a shortened two-week period of work on the two traffic lanes from February 3. Abnormal loads will be prevented from travelling on the northbound motoway until then, followed by a similar southbound restriction for the rest of the project.
Phase three, on the southbound hard shoulder and inside lane, is now programmed to take place from February 17 to May 20 – an additional four weeks of work compared to the originally-scheduled nine – followed by remaining phases on the hard shoulder and central reservation taking the project to the new finish date of June 26.
A statement from roads contractor Amey updated the timescales and noted: “Recent adverse weather has impacted hydro-demolition of the concrete and delayed progress; all our maintenance schemes are dependent on favourable weather conditions to deliver as planned.”
Two traffic lanes are open in each direction throughout the work, centred at the viaduct south of junction 10 at Lesmahagow, which includes waterproofing, concrete repairs, strengthening and barrier upgrades and which will “benefit vehicles using this route by improving the safety and condition of the carriageway and the associated structure”.
With a contraflow system in place to maintain four running lanes for vehicles while the work is carried out, average speed cameras are in place between junctions nine and 11 to enforce the reduced speed limit – “necessary to ensure the safety of roadworkers and road users given the use of narrow lanes [and] considering the high volume of HGV traffic on this route”.
Amey said the work location at the bottom of a hill on a high-speed road which carries a large number of lorries, along with the four-lane set-up meaning staff are working on the same carriageway as running traffic segregated by a temporary barrier, were all factors in implementing the 30mph speed limit.
The company said: “For safety reasons and to maintain a consistent traffic flow, a 2+2 contraflow was the favoured option – this traffic management layout means there is 100 per cent capacity to reduce tailbacks and delays but has meant that the speed limit has been reduced to provide road user and road worker safety.
“Unfortunately, this area of trunk road has historically poor compliance with speed restrictions, so we have had to enforce this 30mph with average speed cameras.
“The speed limit is stepped from 70mph to 50mph to 30mph on the lead-up, which has meant the speed has to be reduced earlier than the works zone to keep road users and road workers safe.
“Based on current monitoring, traffic is flowing as expected. The delays are caused by the additional time it takes to travel through the traffic management at 30mph instead of 70mph, calculated at approximately 4.5 minutes. We thank road users for their continued patience and understanding while these vital improvements are completed.”
*Don’t miss the latest headlines from around Lanarkshire. Sign up to our newsletters here.
And did you know Lanarkshire Live had its own app? Download yours for free here.