I heard, the other day, about a proposal whereby streetlights would be turned off to save energy but could be switched on by cell phone. Odd idea, but it gets the old mind working. I was mostly working in Tucson, AZ for the last few years, and they have a number of observatories near town, so they are keenly aware of what is called “light pollution.” I fly a lot, and have for many years, and I must say the brightness below is really getting out of hand. Remember a barrel of oil saved domestically is as good as a barrel of oil produced domestically. Energy is wealth, and the celestial glow of the city is the glow of would-be prosperity diffusing into space.So how does this apply to PRT? Well let’s imagine the ideal street lighting. First, it wouldn’t blind you, so your eyes could see more with less of it. It would be more uniform, softer. It would shine away from you, not at you. It would be directed mostly toward important things like signs and curves in the road and blind driveways, If there was no one to see it, it would go out, or at least cut back. Intelligent street lighting is an idea whose time has come. PRT could be the platform and catalyst for that change. . This is just one more selling point to PRT that shouldn’t be ignored.