M4 junction 17 traffic and safety problems continue

Concerns over the safety of junction 17 of the M4, near Chippenham, were raised with local police officers during an online question and answer session.

This comes after changes to the layout sparked anger and confusion, with all drivers approaching the roundabout on the A350 from Chippenham now funnelled into the right-hand lane, unless they are turning onto the M4 heading West.

Responding to the comment, Inspector Pete Foster said police had no control over changes to the road layout but added he was aware of “concerns and criticisms” relating to the issue.

The changes were the subject of a planning application in 2018 and are tied to St Modwen Logistics delivering almost one million square feet of warehousing and distribution space.

Many residents have been critical of the scheme labelling it “confusing” and “dangerous” while lengthy queues often form in the right-hand lane of the A350 as a result.

The new road layout (Image: Newsquest)

One resident said: “I don’t feel the new layout is correct… I can see a lot of accidents waiting to happen, it has also caused more holdups along the roads.”

But Wiltshire Council insists the layout is the “most efficient” option.

Cllr Caroline Thomas, cabinet member for transport, said: “We understand that people may have concerns whenever a new road layout is installed, and it always takes some time for people to get used to it.

“Since planning approval for the Chippenham Gateway scheme, both National Highways and Wiltshire Council have worked with the developer to progress the design and delivery of the junction works, which are now complete and subject to a safety audit and ongoing observation.

“Traffic modelling was undertaken to determine the most efficient lane allocation to respond to growing and changing traffic patterns at the junction and this has resulted in the current arrangement.

“This is preferred as it protects the operation of the roundabout, without affecting the safety of the motorway network, and best accommodates the changing traffic flow patterns between the morning and evening peaks.”

Traffic approaching the junction (Image: Newsquest)

A stage 3 Road Safety Audit has been undertaken and the council will subsequently “formalise and improve” the advance signage.

Cllr Thomas added: “The change in lane allocation has resulted in some drivers incorrectly using the left-hand lane and seeking to continue the straight-on movement to the A429, despite signs and road marking lane allocations.

“Since concerns were initially raised, further signs and road markings have been implemented.”