Fresh water has been given to motorists trapped in the closure of the A14 since 5.30am this morning (Wednesday).
Emergency services and highways have spent several hours turning trapped vehicles around in within the closure, although many motorists remain stuck.
Water bottles have been handed out by Northamptonshire Fire and Rescue Service, according to motorists commenting on social media.
Drivers were also praised by others for leaving enough space for emergency services to get through.
Highways England tweeted: "If you are caught within the closure on the #A14 E/B btwn #Catthorpe #M6 #M1 and J1 we are working to get you moving ASAP.
"If you have any welfare issues/ need medical assistance, please call the emergency services. For any further updates, please keep monitoring @HighwaysEMIDS"
The A14 is currently closed eastbound between the M1/M6 junction at the Catthorpe Interchange and junction one near Welford.
It is expected to remain closed until late afternoon / early evening while investigations continue.
HGVs held within the closure are now proceeding ahead past the crash scene in the outside lane after clearance was given by police.
Highways England said: "Thanks very much for your patience throughout this morning."
The westbound side was also closed for several hours this morning following the crash but reopened at around 8.15am.
A spokesman for Northamptonshire Police said: "Motorists are being advised to avoid parts of the A14 following a serious road traffic collision between the M1 and Junction 1 of the A14.
"This section of the eastbound carriageway has been closed after a van was in collision with a lorry shortly before 5.30am this morning.
"Eastbound is expected to remain closed for the morning to allow emergency services to deal with the collisions."