The accident happened near milepost 109 in Middletown Township.
The workers were transported to an area hospital in stable condition, New Jersey State Police said.
They were working as part of a state contractor crew on a road widening project, officials said.
No word on what led to the accident.
The Parkway was closed in both directions for a short time during the investigation.
----------
* More New Jersey news
* Send us a news tip
* Download the abc7NY app for breaking news alerts
* Follow us on YouTube