Burlington Free Press: Here’s the peculiar thing about carpooling: It’s been around forever. It’s easier to arrange than ever, thanks to digital matching of drivers and riders. People have more good reasons to do it than ever, as public efforts to raise energy efficiencies and reduce carbon footprints assume a new urgency. And yet carpooling still enlists a small minority of the car-dependent population, both nationally and in Vermont. In fact, carpooling is less popular today — by a long shot — than it …