You do understand that underground traffic already exists and is called public transportaion or sometimes more specifically like ubahn etc.? The idea in itself

You do understand that underground traffic already exists and is called public transportaion or sometimes more specifically like ubahn etc.? The idea in itself is not new, the idea of him is to put cars under it in a very narrow tunnel because the narrower the cheaper. And now comes the magic stupidity or ignorance of him: There is ar eason why tunnels and our underground looks like it does: Water (rain), Water (ground water), air (oxygen, co2) and emergencies need to be countet for. There is a reason why he still doesn't reach the speed or anything he ever promised on it and there is a reason why 12 years later there is nothing of significance to be seen anywhere. Btw. we could just use transportation technology like in star trek.