Dungan has been travelling along Highway 101 for the past few months, and we had reasonably hoped to hear him revving the daylights out of a hoarse 1968 Ford Mustang, for example, after the fashion of Steve McQueen. Or given that Dungan would be imperfectly cast as Bullitt, he might at least have recorded himself sedately turning on the air conditioning in the Mustang's plasticky modern remake.

But for Dungan, as it happens, Highway 101 is just a route from A to B, or interviewee to interviewee in this case. His aim is to talk to some of the more interesting people who live in California, including the Native American Madonna Thunderhawk, 1960s activist Tom Hayden, and the subject of yesterday's show, Pulitzer prize-winning journalist Lowell Bergman.

Bergman is best known for having been played by Al Pacino in Michael Mann's 1999 film The Insider, which told the story of his collaboration with whistleblower Jeffrey Wigand (played by Russell Crowe) in an expose of the dodgy practices of Big Tobacco company Brown & Williamson.

Dungan questioned Bergman for a while about his early life, and his entry into journalism, and then they spoke at length about the events that led to the making of The Insider. In particular, they discussed the inflammatory decision by CBS not to broadcast the 60 Minutes interview with Wigand, which led to his eventual departure from CBS, and about which he is clearly still bitter.

Unfortunately all that rehashing of old news left little time for Bergman to go into his impressions of journalism today (he has been 35 years in the business and also teaches investigative journalism at Berkeley, so is in a position to judge). He said he believes indepth, objective reporting is on the way out, and that all journalism is moving towards clear political bias, with the various newspapers and broadcasters serving a "niche market of already convinced people".

That sounds like cause for despair, and more examination of the idea would have been useful.

Otherwise, Dungan is really playing a blinder with this series. Now if he would only introduce more cars and dust and gasoline fug and roadside heartbreak motels, everyone would be happy.

Meanwhile, other roads closer to home have also been piquing interest. Reporter Diarmaid Fleming did an exhaustive special on the proposed M3 motorway through Tara for BBC's You and Yours on Wednesday.

Luckily Fleming is an Irishman, so his piece had none of the typical fish-out-of-water foreign reporter's tendency to start looking for blarney the minute they get clear of passport control.

Fleming must have spoken to absolutely everyone connected with the Tara story . . . archaeologists, locals, Tarawatch campaigners, a panicky sounding John Gormley. Then somehow, suddenly, he segued into Dublin traffic . . . though if you're not in the capital, it's hard to draw a straight line between gridlock on Dublin's quays and the desecration of a national monument in Meath.

In a moment of unwitting comedy, a man in Dunshaughlin, where they're desperate for a bypass, said there is archaeology to be found all over Ireland.

"If you go down to the bottom of your garden, you are liable to dig up something, " he claimed. You heard the man. Why are you wasting your time with the Sunday papers when you could be out the back digging up chalices?