For a few years now before green was the thing, I’ve had this idea. It seems kind of obvious to me, and I’m a bit puzzled why it has not happened. See, the real solution for increasing vehicle MPG is not with the vehicle, it’s with the system. By my tracking for over 5 years (another topic for another post), my 4WD Isuzu Rodeo gets about 13 MPG in the city, and 22 MPG on the highway. Most cars are like that. Our Toyota Sienna gets around 16 MPG city and 22 MPG highway (3 years worth of data).
The thing that really kills the MPG is stoplights. You waste all the energy slowing down, then dump all the gas accelerating back up to the speed limit, where you hit another red light and the cycle repeats. What’s really needed is a way to give the driver some feedback on what the optimum speed is to make the next green light.
So here’s how it works. You cannot really change the stoplights — it just costs too much to synchronize them. Sure it can be done, but then you have to squabble over city borders, etc. What you do is add a device to the existing signals. So here goes.
The invention consists of the Monitoring Segment and the User Segment. The Monitoring Segment consists of devices that are installed in existing stoplights that ideally interface with the signal timers and contain GPS receivers. They are configured to know their nearest neighbor stoplights, the contact information for these stoplights, and the distance to those neighbor stoplights. They transmit their own timing information, and also the nearest neighbor contact information and distance.
By using CDMA technology, you can create efficient frequency reusage. Heck, the whole thing could probably be implemented without any FCC registrations by using 802.11 or some ISM band. The important part is that by using a CDMA architecture, you can have low powered local signals that overlay eachother, streaming the contact information (code) for the next signal. To everyone else, including the incumbent user, there’s a higher noise floor.
The user segment is implemented as a receiver in the car. This could be a built-in device, or an aftermarket add-on; think GPS navigation device. It should have a GPS receiver anyway, as the car needs to know where it is in relation to the approaching stoplight. The basic jist is that the car scans for a stoplight RF signal, locks when found, and begins to build a table of neighbors. As the car travels the city, it is picking up timing information for the next stoplight, and is far enough for the stoplight to transmit its timing information to the approaching vehicle. By using the timing information and distance from the stoplight, the device can display the optimum speed that is necessary to make the next green light.
So there. If you do make a device, all I ask is that you send a receiver to me so I don’t have to think about these things while sitting at a red light.
And it’s not my fault my MPG is lousy. See, the improvement has to come from the system side. The government has to solve the problem. Heck, the have an obligation to solve this problem. It’s probably cheaper than synchronization.