The victim had parked on the hard shoulder near Keele services in Staffordshire, between Stoke-on-Trent and Crewe.
He suffered a cardiac arrest after being struck by the lorry and was pronounced dead at the scene by paramedics.
A West Midlands Ambulance Service spokeswoman said: “We received a call to reports of a collision involving a pedestrian and a lorry at 6.19am.
“When ambulance staff arrived they found a male pedestrian, the driver of a stationary vehicle, who was seriously injured and in cardiac arrest.
“The team worked together to commence advanced life support at the roadside.
“Sadly, despite their best efforts, nothing could be done to save the man and he was confirmed dead a short time later.”
A spokesman for Staffordshire Police urged witnesses to come forward to help officers investigate the fatal crash.
He said: “Just before 6.25am, emergency services were called to a report of a collision between an LGV and a driver of a vehicle parked on the hard shoulder on the northbound carriageway, between junction 15 and Keele services.
“Sadly a man in his mid-30s was pronounced dead at the scene.
“The northbound carriageway remains closed between junction 15 and 16 while specialist officers investigate the circumstances of the incident.
“Officers from the Central Motorway Police Group (CMPG) would like to thank motorists for their patience and understanding while this is carried out.
“The family of the man, who has yet to be formally identified, have been notified and are currently being supported by specially-trained officers.
“Anyone who witnessed the collision or has dashcam footage is asked to contact 101, quoting incident number 83 of 27 September.”