Emergency services were at the scene of the smash involving two cars and a van at Junction 1 of the M54 near Wolverhampton.
A woman, a driver of one of the cars, was taken to New Cross Hospital along with a male passenger with injuries not believed to be serious, a West Midlands Ambulance Service spokesman said.
The youngster, whose age has not been revealed, is believed to have been uninjured and taken as a precaution.
Meanwhile the male driver of the van was taken to Walsall Manor Hospital with injuries not believed to be serious.
Two people had to be freed from their vehicles, with firefighters using cutting equipment to release them.
And two children were released before firefighters arrived.
The M54 was closed eastbound at Junction 1, heading towards the M6, while emergency services were at the scene.
Westbound traffic was not effected, with the road back open at 12pm.
A spokesman for West Midlands Ambulance Service said: "We were called to the M54 at around 9am this morning by Staffordshire Fire and Rescue Service to reports of a road traffic collision between junctions one and two.
"There are five patients in total being assessed – there are no reported serious injuries.
"We currently have three ambulances and a paramedic officer on scene."
A Staffordshire and Fire Rescue Service spokesman added: "We were called at 8.50am this morning. Two crews from Cannock attended the scene.
"Two cars and one van were involved in the collision and two children were released prior to our arrival."