A collision between a motorcycle and a truck on Wednesday morning forced all Altona bound lanes of the Western Ring Road to be shut.
The lanes have since been cleared and re-opened with traffic easing through the area.
Emergency services were called to the incident inbound on the Ring Road at the Sydney Road on-ramp just after 8.30am.
The male rider was trapped under the truck for a short time before being transported to hospital in a serious condition.
The female driver of the truck was uninjured and stopped and assisted police.
This closure was under the control of the police with the freeway only being reopened when investigations were completed.
Anyone who witnessed the collision, has dashcam footage or any other information that could assist investigators should contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au
Real-time traffic conditions are available at traffic.vicroads.vic.gov.au
