A rush-hour train or bus is typically soundtracked by the rustle of newsprint, and the tinny beats leaking from headphones. What about those just sitting there doing nothing?
It used to be that the commuting classes occupied themselves with a neatly folded broadsheet newspaper or perhaps a book. Or even a cigarette.
Now, a commuter might read a free newspaper. Nod along to the private beat of their MP3. Text their mates. Play games or catch up on TV on a digital media player. Catch up on sleep. A very, very few take the time to look out the window.
We lead increasingly crowded lives, often cajoled into listening to this album, reading that book, or following another TV show (and made to feel culturally bereft if we don't). Time without connecting into our dizzying global culture seems wasted time.
On a Wednesday morning train service into London, the rush-hour peak has subsided but the carriages are still full of workers, students and shoppers. On one service through Clapham Junction, most read Metro or pick their way through paperbacks.
Every second person seems to wear headphones. Others are texting or making calls on their mobiles. As the train crosses the Thames, only a few glance up to gaze at the muddy river. Reports of the latest celebrity sightings are more compelling.
Ann Johnson, 63, is one of the few making the journey without distractions. She has a copy of the Daily Express at her side, but it's for her sister, who is in hospital.
"I don't normally have a paper. I don't have an iPod, I couldn't have that in my ears," she laughs. "I look at what's going on, what's gone up since my last journey."
Today, for instance, she's been thinking about her sister in hospital. If she's on a shopping trip she'll work out what she needs to buy.
What does she notice about her fellow travellers habits of shutting out the world around them?
"Just that they all tend to be on the phone. I can't help but listen to their conversations. I think people used to talk more. If you're on a long journey and someone's sitting opposite, you'd start a conversation."
On the same service is Laura Jenner, 30, who works for Lewisham Council carers' support. She has her bike on the train, and her backpack on her knees.
"Normally, I've either got a book or I'm listening to an iPod," she says, but today she's tired from her bike ride and just wants to relax.
She's been thinking about a charity run she wants to take part in, in memory of her father who died from cancer two years ago.
"I've been thinking of how I can get more people to sponsor me, so I'm thinking of setting up a Facebook page. Nothing too deep and meaningful.
"I used to drive to work and this is much more relaxing. I would rather go on the overground now."
OK commuter
Student Steve Bamigboye, 34, from Mitcham, would normally be reading the paper but this late-morning trip from London Bridge to Earlsfield is his second journey of the day - he's already read his free newspaper. "I don't want to read it twice."
"I've been thinking about so many things," he says, but won't elaborate.
While he sometimes listen to music on his phone, he thinks it's a shame so many people shut out the outside world. "You can't talk to people when they are listening to music."
On the train to Epsom an hour later, Julia Malykh, a 24-year-old geologist originally from Russia, takes the trip in her stride.
Compared to the 18-hour train ride from Moscow when she visits her family back in Russia, the short journey to work hardly registers.
She spends the time looking out the window, "thinking about my friends, the new friends I have made here in Britain.
"In Russia the trains are a lot busier and a lot more crowded. It's not really convenient to read a newspaper."
But might we be better served if we just sat and watched the world go by more often?
Dr Angela Carter, an occupational psychologist at Sheffield University's Institute of Work Psychology, says there are several reasons why we feel the need to envelope ourselves in words, games or music.
One is to protect our time and personal space, using an activity to take ourselves away from the reality of a crowded carriage. This helps create the bubble needed to daydream, perhaps, about lying on a beach doing nothing.
"People tend to use their time very differently," says Dr Carter. "Some of them will use it to read a newspaper, some like to reflect, some have to have time to use their gadgets."
A commute for some people now might be anything up to three hours - and our modern human minds, it seems, just can't take that amount of time without stimulation.
"If you engross yourself in something, you can make the time pass quite quickly," Dr Carter says.
But you have to choose your distraction carefully. A laptop's no good if you can't get a seat.
"If you're jammed up against someone in a sweaty carriage, then music is a fantastic way to achieve that experience."
Me time
Sometimes, our ability to deal with this dead time is decided by our background.
"If you're an only child, then you're used to being by yourself and you can manage that time quite well.
"You either like spending time by yourself, or you don't. Three hours on a train, for some people, is almost like a divorce."
But, Dr Carter says, it might help to occasionally turn the iPod off, put the book down, and allow our brains to recharge with some time off.
"It's just a personal viewpoint, but I think it's good to have some me time. Just to be more effective. We've got to give ourselves a rest.
"Running from work, watching an action movie on a device and then running off somewhere else to me doesn't sound very relaxing.
"We talk about taking mental holidays - train travel is a perfect time for that. Why wait for your two-week holiday when you can have some of it now?"
I don`t have a 7 series BMW really:cry: