Man charged after trying to bite police

A man who allegedly tried to bite a police officer after crashing his car in Sydney's northwest had to be pepper sprayed before he was arrested.

The man, 29, was involved in two crashes on Windsor Road at Vineyard, near Windsor, after driving his car in a dangerous manner about 8pm (AEDT) on Saturday, police said.

Locals detained the man until police officers arrived at the scene but the man then tried to bite a male officer's arm.

The man also punched two police officers in the altercation, before he was subdued with pepper spray.

The man, from Quakers Hill, was later charged with dangerous driving, assault police and resist arrest.

He was granted bail and will appear at Windsor Local Court on February 12.

The arresting officers received treatment in hospital and have now been released.