TOKYO -- Japan has some of the most congested, confusing, and cramped streets in the world. It also boasts some of the latest technology in zapping computerized data to millions of cars, delivering what may be the world's smartest way to drive.
Car navigation systems in Japan can quickly tell drivers which roads have traffic jams. Using a computerized FM radio broadcast system that collects and sends information from more than 28,000 infrared and radio-wave beacons installed along roads, they can also calculate how many seconds it would take to drive through virtually every block of the nation's cities and then find the fastest routes.
Yet only about a million vehicles -- of the 70 million on Japanese roads today -- take advantage of it.
That's because the most commonly sold navigation systems in Japan give drivers a fraction of the traffic information available.
Equipment offered at dealers is low-grade, and top-of-the-line navigation systems aren't advertised much in Japan.
The better models are also expensive: Equipment costs $950 to $1,900, and the ability to get more timely information adds another $240.
''I'm waiting for our company to put one in," said Tokyo cab driver Keizo Iida, who has no navigation machine.
Another hurdle: Japan Highway Public Corp., the nonprofit organization that oversees the nation's highways and transportation systems, has long been criticized as corrupt and wasteful. The current administration is trying to privatize it to make its operations more transparent and efficient.
Japan isn't the only country where the adoption of smart transportation is taking the slow road.
Electronic toll booths, roads embedded with computer chips and ''intelligent" cars don't involve much cutting-edge technology, but knitting the systems together is complicated. Huge obstacles remain before governments, companies, and the public can agree on standards, methods, and costs to make smart travel a reality.
''To have the whole system, everybody has to agree on how to do it, what kind of technology you're going to use, what kind of standards you're going to use, and who's going to pay for it," said Gabriel Sanchez, a director at Intelligent Transportation Society of America, a Washington, D.C.-based nonprofit group of state and federal governments and researchers. ''And that's extremely complicated."
Without coordinated efforts, smart transportation systems are making baby steps.
In Singapore, the government pushes drivers to use digital road-toll payments. In the United States, discounts on some tolls are offered for drivers paying electronically. Japan also offers such discounts on some highways and bridges.
Sanchez, who visited Japan recently for a conference on transportation, said Japan already leads in telematics, the technology that links cars with computers and telecommunications. That's because both the government and automakers, such as Toyota Motor Corp., are pushing it.
The next generation of telematics can link cars to one another.
In tests by the National Institute of Information and Communications Technology, a Japanese research group, cars connect to other cars wirelessly to get information about a traffic accident or an approaching ambulance.
A picture of an ambulance or a crashed car pops up on the screen when signals are received from other vehicles, and the information is relayed from car to car.
In crowded Japan, even pedestrians could eventually use telematics.
Among the recent research projects are combined glasses and earphones for the blind that pick up infrared signals saying ''red, red, red" or ''green, green, green" as they approach an intersection.