Truck driver seized by public after crash

Bystanders have told how they chased down a truck driver who allegedly drove onto a Sydney footpath and hit an 87-year-old woman in a wheelchair.

Police say the 34-year-old fled after his small truck hit a set of traffic lights in Newtown and struck the elderly woman on Tuesday morning.

The man - who was wearing a moon boot on his left leg - was chased by several passers-by who detained him before he was arrested by officers.

Witness Emil Sayfullim was one of those who pursued the driver.

He heard a "boom" as the truck hit the lights followed by people screaming: "He's running away!"

"I didn't even think, actually. I started to run," he told 10 News.

"Now that I'm thinking later on maybe it will be dangerous. I don't know but (it was) just automatic."

The driver has been taken to hospital for mandatory testing. The 87-year-old was also taken to Royal Prince Alfred Hospital in a serious condition.