Apparently the famous Google self-driving car isn't that close to giving us hands-free transportation after all.

While Google's fleet has safely driven more than 700,000 miles, the autonomous model relies so heavily on maps and detailed data that it can't yet drive itself in 99 percent of the country, according to an MIT Technology Review report.

"The public seems to think that all of the technology issues are solved" with Google's self-driving vehicle, said Steven Shladover, a researcher at the University of California, Berkeley's Institute of Transportation Studies. "But that is simply not the case."

Chris Urmson, director of the Google car team, has volunteered details on the car's limits. He hopes the car will be ready by the time his 11-year-old is 16, or old enough to drive in the state of California.

"It's my personal deadline," said Urmson, as quoted by the MIT Review.

The Google car depends on detailed preparations where the car's exact route is mapped out before the trip, a process far more intensive than the effort needed for Google Maps. Weather is also an issue: Google's much-touted self-driving car has never maneuvered snow, and it's not yet safe to drive in heavy rain either.

MIT notes that the Google car is still better at responding to changes than the average vehicle; for example, a Google car would be able to slow down or stop for traffic or obstacles if a stoplight not on the map appeared overnight.

The Google vehicle will also need a steering wheel in California as of Sept. 16, which is when new state regulations kick in to require a physical wheel and brake and accelerator pedals.

The Mountain View, Calif.-based company plans to develop a temporary brake and steering wheel system for its fleet of test cars.