Watch the terrifying moment a P-plater allegedly speeds through a red light before hitting a grandmother and toddler on a footpath

Horrifying footage shows the moments before an elderly woman and her young granddaughter were allegedly hit by a P-plate driver running a red light who was forced to swerve onto the footpath.

The grandmother, 72, and a girl, 4, were waiting to cross Old Glenfield Road at Glenfield in Sydney 's south-west about 5pm on Tuesday, when a red Toyota sedan allegedly mounted the footpath and ploughed into them.

The 18-year-old behind the wheel was allegedly banned from driving due to a suspended licence.

Dashcam footage showed the sedan moving at speed through the intersection before swerving wildly to avoid a 4WD turning into its path.

Such was the force of the impact the four-year-old girl was thrown into a tree, with emergency responders forced to cut a branch to rescue her.

The impact of crash was heard by nearby residents.

'I hear the boom, this noise,' one local told Nine News.

The dashcam also showed motorists and neighbours rushing to help the injured before emergency responders arrived.

'The road was so busy and police and ambulances were dealing with everything, traffic controllers,' Jwanah Rahem said.

The grandmother was rushed Westmead Hospital in a critical condition, where she remains with serious head injuries.

The girl was also taken to Westmead in a stable condition but has since been discharged.

Police established a crime scene that was examined by specialist police from the Crash Investigation Unit.

The P-plate driver was taken to Liverpool Hospital in a stable condition and since been released.

NSW Police told Nine News they plan to speak to the 'in the very near future'.

A police spokesperson told Daily Mail Australia on Thursday night that no charges have yet been made.

Investigations into the crash continue.