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The idea is to use barcoding for transferring automatically information from the road to the car computer system. The road barcode is a tape crossing the road (or a single lane). This tape is a set of white broad and narrow bands according the construction of barcode used (for example CODE128). It looks
like a giant barcode extended in height and placed on the road. The care has a simplest barcode reader looking down. The reader catches the code when the car is passing the barcode tape. No additional scanning is needed. A lot of information could be coded like following: roads ID, mileage, traffic sign codes and so on. I believe that such barcoding road-car transmitting system could be cheaper then now developed radio smart road systems or GPSs.
||A similar technology already exists with rail cars. The cars have the barcodes on them, though, and the detector is stationary. Applying this to cars is certainly a good idea.
||The only issue is that the barcodes would have to be quite complex. If one were installed at every intersection (as would be needed with a guidance system), there'd be millions of codes that would need to be stored. Two-dimensional codes might overcome this.
||I picture myself backing up, turning slightly, and driving forward again over and over again. Just like what happens at the grocery store. I suggest you use a 2 dimentional bar code. The ones that look like a bulls eye that UPS and FedEX use. If you block any part of code128 the string is invalid. Some 2 dimentional codes can be blocked as much as 60% and still read.
||Alot of inventory control systems are going away from barcode and using RFID tags (also used in Mobil Speedpass and High speed toll lanes)
||Just reverse the system and put the RF reader in the car, and the tags, powered or passive in or near the road. Cost for an RF receiver would be comparible to the cost for a barcode reader, the "tags" are a few dollars each, can store more info than your standard barcode, and could be placed permanently on road signs etc. to provide data ( Lodging, this exit), or temporarily (construction ahead - 2 miles) as desired. Some chips are programmable, so the message can be changed as needed.
||Sure 2D barcodes and RFID tags have much more info volume.
But the difficult questions related to both are following:
1. How to target the reader to the barcode (tag) automatically?
2. What is a proper location of labels on the road surface or sideways?
3. How to avoid masking effect then one car puts the shadow to others?
4. How many labels are needed ?(one per lane?)
5. Materials and methods of installation
6. Distance between reader and target label
1D barcode stripe have not such problems.
Barcode stripe can be just painted onto surface of the road
The reader is on a bottoms of the car (no target system, close distance).
Barcode stripe is a single for full road as it cross all lanes of both directions.
Cars pass the barcode stripe independently and dont meddle others.
Problems of 100% rate of first reading is solved by multiple scanning or matrix readers.
Moreover the error rate of reading depends mostly on curvature of label surface.
In our case the flat surface is guaranteed.
About the complexity.
Simple barcodes are mostly are used for identification purposes not for transfer big messages.
In our case barcode traffic stripes could play roles of milestones.
The possible structure of the code :
CCC 3-digit country code
RRRRRRRR 7-digit ID# of the road
SSSSSS traffic sign code.
That is 16-digit numerical code.
If you take the module width (minimal width of bar) equal 0.5 cm.
Then the total width of barcode stripe (of CODE128) will be about 62 cm.
The map should be stored in the car computers and could be updated regularly in service or gas stations or by Internet. The passing the barcode traffic stripe just gives the cars location for pointing on the map and some limited local traffic info coded in last part of barcode.
||Could cause confusion at zebra crossings!
||What do you do if the sign doesn't scan? Back up and try again? I've noticed that even professional check-out girls often fail the first 4 or 5 times. Why would a vehicle be any better, especially when skid marks over PREVIOUS mis-scans made reading more difficult?
||Annoying beeps could be deleted just by turning off the sound. Snow is more difficult.
Signs dye can include metal powder and then be read by inductive, capacitive or magnetic reader through the snow or dirt on the surface of the road.
The color sign of is to be any except white to avoid confusion at zebra crossings, barcode stripe is narrow, bars are directed cross the lane.
Again the error rate of reading could be reduced up to zero by scanning, matrix reader and addition reader system as mentioned above.
Positioning function of such system are more important then the warning, so the value of error no reading is not so high. Positioning in cities (where GPS works not so good) is more important then in the country. Snow problem is not so hard in cities.
||As TitaniumZ says, using RFID tags the reverse way embedded in the road lane (or near) is the best alternative idea; costless, sustainable (no batteries ever), vandal-free, etc. We are currently developing this approach, having obtained an international patent years ago and looking for a pilot. More details can be provided on request or here: www.roadbeacon.com