As the show's special week of 50th anniversary episodes begins tonight, an explosion at Nick and Leanne's Joinery bar will cause a tram to fall from the viaduct above and onto the cobbles, causing death and devastation.
Despite the spectacular scenes in store, programme bosses have always insisted that the characters will remain at the heart of the anniversary storyline and its aftermath.
Speaking in a new interview with The Guardian, Roberts commented: "We have to be careful that we don't do gimmickry. Character always comes first. Going right back to Tony Warren's first episodes, they didn't have huge storylines but they had characters that leapt off the screen.
"The tram crash is just a catalyst for real drama. Yes, we're crashing a tram into the cobbles but we're really crashing a tram through the lives of these characters, turning their lives upside down and examining the consequences for their relationships through powerful drama."
He added: "It's important to do justice to the 50 years and the show's tradition. But even when we plotted out the crash, we were thinking about how this would be a springboard for what we'll be doing into next year and way beyond that."
Bill Roache - who plays Ken Barlow on the show - previously said that the tram crash will spark some "amazing" follow-up storylines. Get the Inside Soap magazine on your iPhone or iPad