The scheme will affect the part of the motorway from junction 10 at Burnley to junction 14 at Colne which is maintained by Lancashire County Council.
Allowing the hard shoulder to be used for running traffic will mean the existing two-lane capacity of the motorway can be maintained when one lane is closed.
In the short term, this will help to reduce delays during a major project to replace the central barrier, which is currently proposed to take place in 2015, but will also help to sustain capacity during future works beyond this.
The improvements will strengthen the barriers next to the hard shoulder and bridge parapet walls to reduce the risk of vehicles going through them in the event of an accident.
The work will start on Monday, July 21st and take approximately 22 weeks, with the scheme scheduled to be completed around the end of December.
To allow the work to be carried out safely, while minimising disruption as far as possible, a section of around 1km will be reduced to one lane at any one time. Work will begin at Colne, progressing to Burnley along the westbound carriageway, before returning along the eastbound side.
Oliver Starkey, highways manager for east Lancashire, said: “This scheme is vital to improve the standard of the safety barriers on the M65 and will also help to reduce delays by allowing two lanes of traffic to be maintained during future works.
“We’ll do our best to minimise disruption and, where possible, look to avoid working when we can expect the motorway to be at its busiest, for example on days that Burnley FC are playing at home.
“We’re sorry for the inconvenience and would ask people who use the M65 to leave extra time for their journeys while the work takes place.”