Giant Rare earth magnets placed on cars drive over giant coils in roads to generate electricity. The electricity generated pays the toll as cars move across the road. The electric is sold on the grid or even sold to recharge electric cars to generate revenue. That way roads would pay for themselves. I wonder if electric motors would make a large enough field to energize coils like those of the Tesla?-- travbm, Nov 19 2015 MacGuffin https://en.wikipedia.org/wiki/MacGuffinMacGuffins keep the world moving forward. [travbm, Nov 19 2015] To be fair, he's not predicating it on efficiency, but as a usage fee. It doesn't begin to approach a simple mileage fee for fairness, or a gas tax for ease of use, but it's not completely impossibly impractical.-- MechE, Nov 19 2015 Yeah it is impossibly impractical even with bifilar pancake coils. Even when placed all though out the entire length of segment of toll road. But I thought it little macguffins was what the half bakery was about. Though you could put solar panels over top the coils. and drive over them. I figure even about 1,000 pound pull strength magnets moving at 50-70mph would do the trick. Besides you can't power an electric car fleet on just coal and oil if the technology existed. It may be cheaper to have used compressed air. I like Macguffins.-- travbm, Nov 19 2015 What about a coil wrapped around a tunnel, kind of like a reverse solenoid?
If the tunnel's on a downhill, it would pay the toll and slow you down at the same time without burning gas.
//But I thought it little macguffins was what the half bakery was about.
Say what?-- the porpoise, Nov 19 2015 That's what you get for not reading the help file. MacGuffins are plot devices "with little or no narrative explanation." (your link.)
From the help file, on the other hand: "Generally, the more you know (and can explain!) about the technology behind your invention, the more interesting the posting will be. As always, when in doubt, write about something you know."
(Note that that's not a hard and fast rule. I've posted several ideas which have a distinct lack of explanation, relying on the reader's imagination and sense of humor to create the imagery. It's not easy, and it's not appreciated when it doesn't work.)-- lurch, Nov 20 2015 Sp.: "Magnetic cars Road troll"-- MaxwellBuchanan, Nov 20 2015 Who wants to read about a plasma induction capacitor? Most ideas I did have I did and failed at. And what I do know no body seems to want to hear about.-- travbm, Nov 20 2015 What are you complaining about? You got buns.-- the porpoise, Nov 20 2015 Yeah I got buns by being a buffoon.-- travbm, Nov 20 2015 Stick to doing what you're good at.-- MaxwellBuchanan, Nov 20 2015 If that is the case I am great at electrocuting myself with microwave capacitors.-- travbm, Nov 20 2015 Keep at it.-- MaxwellBuchanan, Nov 21 2015 I must be bord to keep trolling my own post. I may need to go to church and purge myself of what ever evil is in my heart through Jesus Christ.-- travbm, Nov 22 2015 Oh heavens. Please don't mention religion in this place. It never ends well. Ommmmm-- blissmiss, Nov 22 2015 Don't worry, It was just gas.-- travbm, Nov 22 2015 random, halfbakery