Answers were last night demanded after a crash on the A14 led to part of the road’s closure for almost six hours – again causing lengthy delays on one of the county’s major routes.

Engineers worked overnight to repair a 100metre stretch of central reservation damaged when an HGV ploughed into it on the A14 westbound near Haughley at around 3.15pm yesterday.

Both carriageways between junctions 47 and 49 were closed for almost four hours, prompting tailbacks for rush-hour commuters and heavy diverted traffic in nearby villages.

The inside lane of the westbound carriageway reopened at 6.50pm before the inside lane of the eastbound carriageway, which bore the brunt of the crash, finally reopened at around 9.15pm. The outside lanes of both carriageways were expected to reopen before 6am today.

Last night, Suffolk MP David Ruffley and the county’s police and crime commissioner Tim Passmore condemned the response to the single-vehicle accident as “unacceptable” and pledged to launch an investigation.

Mr Ruffley said: “The A14 is the main arterial road connecting East Anglia to the continent and the Midlands, so very serious delays like these are not even remotely acceptable.

“The first port of call is to get the police report to find out what happened. Was there enough manpower? Was equipment to extricate the lorry there quick enough? An investigation is a matter of urgency.”

Mr Passmore said he was “surprised” over the time taken to resolve the incident.

“Situations like these are unsatisfactory and unacceptable,” he said. “The Highways Agency must have a quick response and roads must reopen as soon as possible.

“We have very quickly got to come up with systems for the entire A14 in Suffolk to deal with these accidents. We need to have proper, recognised diversions which need to be enforced to prevent people’s lives from becoming a misery.”

Engineers from Skanska, working on behalf of the Highways Agency, arrived at the scene with a crane at 5.20pm, a Suffolk Constabulary spokesman said. The lorry was removed at around 7pm.

Mr Passmore added: “If it is the case that the Highways Agency took two hours to get there, that makes me very cross. I am not prepared to put up with this. It is not good enough.

“By definition, the quicker they get there, the quicker they can assess the damage and carry out the required work.

“The police debrief will find out exactly what happened and will be discussed with the Highways Agency, but this is an ongoing problem which needs to be resolved.”

Graham Newman, Suffolk County Council’s cabinet member for roads and transport, said questions will have to be answered at upcoming meetings between the council, police and the Highways Agency.

“Clearly the present situation is not adequate,” he said

“We are trying to get more local deployment of specialist kit. Some of it comes from very long distances – sometimes from the other side of the M25.”

A Highways Agency spokesman said: “We are committed to providing safe and reliable journeys for all road users in East Anglia and are committed to working with police and other emergency services to reduce delays following incidents.

“We do have a formal debrief process following any incident, which is helpful so that all parties involved can discuss and share any lessons to be learnt.”

One lane of the A14 remains closed this morning between J47 and J49 as work is carried out to repair the barrier.