The good news is that there's hope, confirmed in a recent book that I can highly recommend to anyone interested in transportation: Transport for Suburbia: Beyond the Automobile Age by Australian researcher Paul Mees (Earthscan, London, 2009).
He points out that the in the past 20 years the density of many European cities has declined significantly, as they have allowed urban sprawl on their outskirts. Yet, these areas have much better public transport than almost city in the US with much higher density.
But Transport for Suburbia is not primarily about density, it's a very readable discussion of the elements high quality public transportation. The basis, Mees argues, is the "network effect" - providing convenient frequent service with easy transfers, allowing rider to get anywhere from anywhere on the network. In larger cities this would be high density rail, or bus rapid transit (busways), with feeder buses. He provides examples showing cities with such systems are more efficient and require less subsidy than other services.
Besides density, Transport for Suburbia takes on some of the sacred cows of transportation planners. His chapter on privatization is a treasure and he provides recommendations for how agencies can handle it. He argues that traffic congestion on highways is more effective in getting people to consider alternatives than are tolls and congestion pricing. Along the way you'll learn how the Swiss are able to provide high quality service with longer headways using a technique called "pulse scheduling" and (spoiler alert) why GM isn't responsible for killing the red-line trams in Los Angeles (since ridership was already in decline. And, Mees describes a transit system in a city of 44,000 people that offers 10 minute bus headways 6 days a week and has a higher transit mode split than London! (Answer: Schaffhausen, Switzerland)
The book concludes with a series of recommendations that summarize his points very nicely. If there's anything lacking in Transport for Suburbia, I would have liked a few more illustrations and charts. Parking disincentives for cars are mentioned only in passing and I think he underestimates the value of behavioral change strategies like TravelSmart, individualized marketing programs. But those are subjects for other books. And, for what it's worth, he doesn't mention carsharing.
The book is written for citizens as well as planners - it's low on the jargon and is "just right" at 200 pages. You can sample some of the pages from Transport for Suburbia in this preview.