The A50 was closed this morning after a crash involving a tractor, a combine harvester and a van.
Emergency services were called to the scene, near Sudbury, shortly after 5am this morning to reports of a three-vehicle collision.
Derbyshire Roads Police and Highways England closed the dual carriageway while the incident was dealt with.
One eyewitness, who was first on the scene, said the tractor had toppled over as a result of the crash, which also caused a lot of damage to the van and combine harvester.
Eyewitness Jon Moss told Farmers Guardian: "How the van driver and the tractor driver made it out of that was beyond me.
"I bandaged up the tractor driver’s head and the chap who was in the combine rang 999, but didn’t know where we were so I spoke to the emergency services on the phone.
"I then moved them all away from the crash as the van was smoking and diesel had spilled onto the road.
"They were all pretty shook up, understandably, and I’m just glad they are OK."
A spokesman for Derbyshire Police said: “We were called at 5.02am to reports of a collision on the A50 involving a combine harvester.
"Initial reports from our officers at the scene suggest that four vehicles were involved - two trucks and a combine harvester - but it is unclear what kind of vehicle the fourth is at the moment.
“No one was injured, but the road is closed - we’re diverting traffic off at the slip road and back on at the A515 turn for Ashbourne. Police are still in attendance.”
Farm Safety and Transport Advisor Tom Price said: "The full details of the accident are not known but farmers must take care whenever moving vehicles on the road but especially when travelling on dual carriageways.
"Remember amber beacons are obligatory on all agricultural vehicles with a max speed of 25 mph using dual carriage ways or roads with a speed limit over 50 mph. Beacons should also be used by slow moving vehicles and escorts."