I do personally think that there's a problem with the worlds global usage of motorized transport. It seems as technology is continuing to develop new ways of making cars more efficient more people probably feel less guilty about driving so they avoid walking or riding a bike. This graph from the environmental protection agency suggests this, http://www.epa.gov/oms/invntory/overview/vmt.htm. It's good to see that car companies are trying to make cars more efficient but surely they're just working in vain if people are just going to drive more anyway?
As a student at University, transport is very important to me I live down in the South West so I am a good 4 hour drive away from home and the fact that I'm student means I'm not the richest of people at the moment. So when I search for train tickets and find out that it's going to cost me almost £100 there and back I can see why so many people have their own forms of transport. Firstly cars these days are very reliable, you can drive them when you want, you can easily transport a lot of stuff and it's probably cheaper in petrol costs as well. Public transport is often overpriced, unreliable and not a very comfortable way of travel.
When just commuting around Northampton town I use the bus service, I find here that it's very reliable and the fact that it's free also helps. However if I could afford to purchase a bike I would definitely do so, it's free to run, can get you from A to B quickly. you can travel when you want too and it keeps you active. I can't understand why more people don't choose to cycle, there are enough warnings in the media about how obesity is becoming a national problem so you would think people would turn to cycling to try and reduce it.
There are websites that are trying to get people to cycle more, like this one for example http://www.bbc.co.uk/bloom/actions/cycleandwalk.shtml#quickjump. It's a good website to look at if you want to find out how you can make a difference to yourself and to the world by just changing the way you travel.
Having said this I do think the benefits of flying are very good, even though it's very unsustainable I believe the freedom created by being able to travel to any country in the world is amazing plus. There was recently a debate caused with Heathrow by adding another runway to the airport, http://www.guardian.co.uk/environment/2008/jan/27/travelandtransport.carbonemissions1. As I'm not a regular flyer I can't really see it's needed as there are enough flights as it is.
I think the government has to try and make more people use public transport as it's obviously far more sustainable than people driving everywhere. This report from the government on climate change and transport has some interesting statistics on the public's perceptions on the topic, http://www.dft.gov.uk/adobepdf/162469/221412/221513/4387741/climatechange.pdf.