The A312 in Hayes was shut for more than two hours after a man threatened to jump from a bridge.
The Metropolitan Police confirmed The Parkway was shut at the Ossie Garvin Roundabout at around 12.15pm.
It is understood the road reopened at around 2.25pm.
The man has been taken to hospital.
Police have praised a passer-by who may just have “saved a life” after retelling the police about a man threatening to jump from a bridge at the Ossie Garvin roundabout.
Police closed the A312 and “surrounding roads” while they talked the man down from the bridge.
He has since been taken to hospital.
Our full report can be found here.
That concludes our live coverage of this incident.
"Sounds like you saved a life"
Police and ambulance services rushed to the scene after a member of the public reported the incident.
Individual taken to hospital
The man has been taken to hospital, Hayes Police wrote on Twitter.
According to a Met Police spokesman, authorities and emergency services closed all surrounding roads near Ossie Garvin Roundabout to avoid traffic going under the bridge.
Similar incident in 2016
Last year, emergency services talked down a man from the same bridge at the Hayes by-pass.
The man was taken to hospital for treatment under the Mental Health Act.
Read more here
Traffic still slow
At around 2.30pm, TfL tweeted that A312 The Parkway had re-opened in both ways.
Traffic is still slow. More traffic updates here
Police and emergency services at the scene
Police and ambulance services rushed to the scene at around 12:15pm.
A312 The Parkway partially closed
At around 12.30pm, the A312 The Parkway was closed between Willow Tree Roundabout and M4 due to a “police incident”.
According to the Metropolitan Police, a man threatened to jump from a bridge.
Traffic is moving slow at Ossie Garvin Roundabout, in Hayes, as the police is trying to talk a man down from a bridge.
More traffic updates here
Good Afternoon West London
Good afternoon everyone - we will be bringing you live updates on this ongoing situation as we get them this afternoon. Stay tuned.