The narrow path along the busy Crowthorne Road - between Kingsley Close in Crowthorne and Longdown Road in Sandhurst - is frequently used by cyclists and schoolchildren.
But police have labelled the road and path as dangerous because of its narrow width and lack of cycle track.
The problem has caused residents and councillors much concern over the past five years, prompting Sandhurst Town Council to make several attempts to gain funding from Bracknell Forest Borough Council in a bid to improve the path's safety.
Until now there have been insufficient funds available.
But after months of stalling, work is finally underway to widen the path to three metres - this will include a cycle-track, street lighting, signings and markings.
Cllr John Mason, chairman of Sandhurst Town Council's environment committee, said he was delighted the plans were finally taking shape.
He said: "This has been one of the paths I have wanted to see changed since I first became chairman over a year ago and I believe it was a council item for some time before I arrived.
"Cycling along the Crowthorne Road is very dangerous and has been called so by the police.
"By taking cyclists off the road, it will improve safety for them and motorists too.
"But what we really wanted to see was improved safety for school children at Edgbarrow School who use it every day."
Cllr Mary Ballin, executive member for Bracknell Forest Borough Council's environment committee, said: "I am very pleased work has commenced on this much needed widening scheme.
"The finished footpath and cycle-track will cater for all users' needs under improved safety conditions.
"The council is very keen to encourage more cycling in the borough and this can only be done by making paths safe for both cyclists and pedestrians."
Earlier this month Bracknell Forest Borough Council began work on widening the entrance to Wildmoor Heath.
The improvements are set to be completed by August and will initially involve clearing the site and cleaning the ditch.
Temporary traffic signals will be in place over the coming months to protect pedestrians, but these will be removed overnight to reduce inconvenience to motorists.