Some eight fire engines and numerous emergency workers tackled the blaze which caused black, acrid smoke to drift across the M65 after the fire broke out in Accrington, near Blackburn.
At least 120 cars were destroyed by the fire in the Moorfield Industrial Estate.
Firefighters were forced to use water from the nearby Leeds/Liverpool canal to try and quell the blaze.
A statement released by the Lancashire Fire and Rescue Service said: “The firefighting is having the desired effect of putting the fire out, though firefighters will be at the scene for some hours yet.”
Nearby residents were instructed to steer clear of the area
Crews battled for around seven hours to bring the fire under control after it broke out around 4pm on Sunday afternoon.
They remained at the scene until dark extinguishing any remaining pockets of fire and damping down.
At least 120 cars were destroyed by the fire in the Moorfield Industrial Estate
The cause of the fire is being investigated
Firefighters doused the flames, and worked to ensure the polluted water running off the fire did not enter the water system.
Nearby residents were instructed to steer clear of the area and close all window and doors.
Get Quotes on Home Insurance
Firefighters were forced to use water from the nearby Leeds/Liverpool canal
The cause of the fire is being investigated, and no one is thought to have been injured.
A spokesman for the Lancashire Fire and Rescue Service said: “It’s as yet not clear that the fire was started deliberately. We’re still gathering evidence.”
Some two engines came from Hyndburn, two from Burnley, two from Blackburn, Great Harwood and Rawtenstall and Fulwood's Command Unit all attended the fire.
Support appliances and crews also assisted.
— Tracey Cooke (@Traceys_Crafts) April 9, 2017
50 cars on fire at scrap yard, Moorfield Drive, Altham. 8 fire engines and crews. If you live in the vicinity keep smoke out, shut windows.
— Lancashire Fire (@LancashireFRS) April 9, 2017
The site also saw another devastating fire in December, when around 400 vehicles caught fire.
More than 80 firefighters from 16 stations battled the blaze which saw two eastbound lanes closed on the M65.
A hazardous materials unit joined firefighters after a “strong breeze” fanned the flames.
Live images: New York's Chelsea Market on fire Tue, March 28, 2017
A major fire has broken out on the roof of Chelsea Market at 75 Ninth Ave in New York. The entire building has been evacuated
Twitter 1 of 10