It's been a morning of chaos for commuters after two separate car accidents on Sydney roads.
Traffic is already backed up four kilometres on the M7 at Glenwood, where a car is upside down following a truck and car accident at about 8.40am.
One of two city bound lanes has been closed while emergency services work to clear the crash.
It follows an earlier crash at Horsley Park just after 6am involving a ute and a van, which left two men seriously injured and trapped inside their vehicles.
It's believed that a third car travelling behind the van was unable to stop after the initial crash near the intersection of Chandos Road and Wallgrove Road and also collided with the wreckage.
Emergency services worked to free the drivers of the ute and van, who have since been transported to hospital where they remain in a serious but stable condition.
Significant delays at both crash sites are expected and motorists are advised to avoid the area completely until the traffic is cleared.