It doesn't take a degree in economics to predict that increasing incomes and vehicle availability will reduce carpooling. Increased dispersal of workplaces and increasingly informal approaches to working hours and freer form working arrangements will also make carpooling with its set schedules and daily routines less attractive. Planners in Washington DC want to put an increasing number of American commuters in carpools. Under current legislation and regulations federal money is difficult to get for any expansion of urban highway capacity except for special carpool or HOV lanes. Perhaps the thinking is that if congestion in general traffic lanes is so unbearable people will carpool.
People have sound reasons for their choices.
He notes that American commuters are resilient and innovative and simply won't be organized by planners to do things that are unreasonable to them. Like transit, many new HOV lanes look as though they are going to be embarrassingly empty. The good news is their conversion to more productive uses will be relatively cheap. The HOV lanes will be able to be converted to express toll lanes, to automated highway lanes, or simply turned back into general purpose lanes. Investments in misguided rail transit are not similarly recoverable.