On my first visit to the United States, around 1980, I ended up riding the Space Mountain roller coaster in Disneyland in California with a bunch of off-duty police officers. Having gone into journalism to be a rock critic, I’d somehow ended up starting my working life on Police Review, the independent journal for coppers, which had organised a trip to Los Angeles with a policing theme, including a visit to the FBI academy and a women’s prison. While I was there, staying at the Hollywood Roosevelt Hotel (which, judging by its website, is a lot funkier than it was then), I went for a stroll one evening along Sunset Boulevard — just for the hell of it, just to see how far it would go. I didn’t know: I hadn’t yet got into the habit of reading guidebooks and making notes on maps before a trip. I walked and walked, until I got conscious that it was getting dark and — this being a city in thrall to the automobile — there was no one else walking, and then I turned back for the hotel.

Laura Barton is made of sterner stuff. She has walked all 22 miles of Sunset, from the city to the coast, for a Radio 4 programme being broadcast in two parts, starting on Thursday morning at 11.30. Her aim, according to the previews I’ve read, is to see what the street, and the portrayals made of it over the years by writers and artists, can tell us about America.  If 24 Hours of Sunset is anything like her Notes from a Musical Island, which was broadcast earlier this year, it should be well worth a listen.