According to new legal docs, obtained by TMZ, the Fellows family is going after Warner Bros. Discovery and Lions Gate Entertainment ... accusing the media corporations of negligence they insist led to Ryan's death.

In the docs, the family says the area where 'Street Outlaws' filmed drag racing scenes was a dusty, weather-beaten, rough asphalt 55-mile per hour roadway in the Las Vegas desert, which didn't meet any of the industry safety standards for drag racing.

TMZ broke the story ... Ryan died back in August in a fiery crash during filming for his popular Discovery show. We were told Ryan was racing another driver when he lost control of his car near the finish line, with the vehicle rolling before catching fire.

In the docs, Ryan's family says the roadway where he crashed was only 12 feet wide instead of the industry standard of 30 feet. They also say the sides of the road featured broken asphalt and gravel shoulders with sheer drop-offs, instead of the industry standard concrete barriers.

Ryan's family claims there were numerous crashes during filming, including cars flipping, rolling and catching fire ... and they rip the media giants for filming life-threatening collisions and airing them on TV for profit.

The family claims the rough asphalt caused racecars to lose traction, the narrow lanes left drivers no room for corrections and the gravel shoulders and drop-offs sent racecars into out-of-control slides that only ended when the vehicles dug into the sand, flipped and rolled.

The Fellows say Warner Bros. Discovery knew it was extremely dangerous to hold races on the roadway ... and they claim it was an "extreme departure from what a reasonable careful person would do in the same situation to prevent harm to others."

It gets worse ... Ryan's family says Warner Bros. Discovery had multiple opportunities to move filming to a safer location after "numerous horrific crashes," but they say the network instead "sat back, flipped on the lights and cameras, and waited for the next inevitable crash."

That crash happened August 7, when Ryan's family claims his racecar lost traction on the roadway, slid off the road and flipped into a roll. The Fellows say Ryan's car rolled multiple times before coming to a rest upside down and catching fire, and they claim he hung upside down in the driver's seat on fire for more than 30 minutes before fire crews removed him from the car. By that time, the family says Ryan was horribly burned and dead.

The Fellows say after Ryan's death Warner Bros. Discovery moved the show to a dedicated 75-foot-wide drag strip at a professional California raceway ... and the family says the change "proves the availability and feasibility of a safer alternative to the unsafe desert roadway."

Ryan's family is now suing the media companies and they want punitive and compensatory damages because they say his death is causing suffering and loss of love and companionship.