Cassette Navigation 1971

Imagine a GPS (or SatNav, if you're British) in 1971. There was such an idea, but it came on pre-recorded cassette tapes that gave you directions as you played it. Watch how it works in this clip from the erstwhile TV show Tomorrow's World. Of course it could never work as advertised. If you ever made a wrong turn, the whole system would suddenly turn useless. Or if you were caught in a traffic jam, didn't drive the speed the cassette expected, or the machine ate the tape- which was a common occurrence with cassettes. You would need to buy a new cassette for every new route, and once you drove there, you wouldn't need that tape again. I'm sure there are more reasons not to buy into this system. In 1971, it was easier to learn to read signs and maps, develop a sense of direction, and ask someone as a last resort. (via Nag on the Lake)