Both mum and baby are doing well after PC Robert Morgan helped with the delivery after being flagged down in the middle of his shift.
The new baby girl doesn't have a name yet but she's happy and healthy.
More top news
Jodie Hills is calling for a boycott of a nightclub after she claims she was pushed onto railings outside. Contains graphic images.
A 3-year-old from Tower Hamlets is among hundreds of London kids identified as potential extremists.
The shipment was found by a worker as he unpacked bananas. Police say they are investigating.