> Use one of the lanes? Yes, definitely. They'd have to be physically isolated from the heavier higher-speed traffic, and there's some complexity around provid

> Use one of the lanes? Yes, definitely. They'd have to be physically isolated from the heavier higher-speed traffic, and there's some complexity around providing safe on/off ramps for both traffic types, but it's all solvable. The bigger issue is that it only addresses riders' longer-distance travels. The more difficult issue is shorter distances in cities and on secondary suburban roads. Shuttling kids around and various other day-to-day errands constitute a majority of non-commute driving for huge numbers of people. What do you do when the road only has one lane in each direction already, directly abutted on all sides by private property? That's the part I don't see a solution for. The only thing I can think of (which also helps address some of the "borrowed highway lane" issues) is fully elevated bikeways, which is hardly cheap or visually appealing but at least seems feasible financially and politically.