Some sporting documentaries can appeal to those who have no interest in the sport - Senna, The Crash Reel etc. - and there are those who will struggle to break out to interest those beyond their core support. Despite ramping up the very human element of the road racing dynasty that is the Dunlop family, Michael Hewitt and Dermot Lavery's documentary does not manage to pull off TT3D's broad appeal.

Why does the road racer do it? It's a dangerous sport, with numbers of fatalities and major injuries up there. And how do they do it? How can they concentrate travelling at that speed? Road opens with a terrific quote from Milan Kundera who tries to sum it up: “The man hunched over his motorcycle can focus only on the present... he is caught in a fragment of time cut off from both the past and the future... he has no fear, because the source of fear is in the future, and a person freed of the future has nothing to fear.” That's why so. That must be a wonderful, if scary, feeling to experience. No future. In contrast Liam Neeson's narration is rather simple and heavy handed, reading like an Introduction To Road Racing 101 voiceover.

Hewitt and Lavery do their level best to take Kundera's words and render them visually, coming up with the goods with a sensory overload: music is thumping, there's an emphasis on the WOOSH as the bikes fly past, and the POV shots exhilarate (but there are not nearly enough of them). Hewitt and Lavery stick close to the their theme throughout - ultimate glory and terrible tragedy will always remain a hair's breadth from each other - and the audience is on edge every time there is race footage. All of this gets the pulse racing.

However, the emphasis on the talking heads that recall the tragedies that befall the Dunlop family (Joey and brother Robert both met their death on a course) can smack of TV. Interviews with Robert's sons - William and Michael - stop short of getting under the fingernails of what it means to continue racing despite losing a father and an uncle to the sport.

As a documentary on the Dunlop family, Road is worth checking out, but it outstays its welcome and keeps newcomers to the sport at a distance.