In the US, because the main roads are so crowded, they introducted High Occupancy Vehicle (HOV) lanes to encourage carpooling. As a result, a social practice known as "slugging" formed where, in symbiosis, people wanting a ride would gather at specific destinations, and a single driver would pick them up, allowing them both to use the much faster HOV lanes. Apparently Virginia officials said that most of the 35,000 or so carpoolers who use the I-95 HOV lanes daily are "sluggers".
This practice could be greatly reduced as state governments are rushing to convert the HOV lanes into HOT (High Occupancy Toll) lanes. Basically it's a way to buy yourself out of the traffic that the rest of the cheap-ass proles have to sit in. Plastic has a discussion on the subject.
I think the US needs a major rethink regarding public transportation infrastructure. I prefer to take public transport - I don't own a car, and while travelling for work I examine other options before renting a car. And sadly, when visiting cities in Europe, I have *never* rented a car, and in the US I almost always have to do so.
My understanding is that public and alternative transportations make up an ever smaller percentage of the DOT budget - when transportation needs to be looked at as a whole. If there is a way to save $2 on highways by spending $1 on public transport then these options need to be examined.
I am very pleased to see Ottawa plan to move forward with the O-Train extensions to utilize existing rail lines (cheap!) and extend the existing infrastructure. Ottawa is a wonderful city for getting to and from downtown, but my commute to Kanata means being a "slug".