My Google search for "test driven design" got me Test-driven_development as a first hit. That is a short article that hits the high points and directly answers your objection - the tests fail until the code they test is written and is correct (at least in the eyes of the tests).

TDD is a technique I use occasionally, but in each case I've used it the result has been spectacular success. When I have used TDD I've also used code coverage to ensure a sensibly high proportion of the code is tested. In my experience the result was seeming slow progress, but substantially bug free and easy to maintain (i.e. high quality) code as a result.

Not all projects can use TDD. My day job is writing hardware specific embedded code for in house developed systems. Testing software embedded in hardware is challenging!