If something sounds too good to be true, it probably is.
We’ll admit that was our first thought at the news earlier this week that an Elon Musk company would build a tunnel between downtown Nashville and the Nashville International Airport, and that it would cost taxpayers nothing.
The thought, after all, of tunneling for 10 miles below a city and under state-owned roads seems patently ridiculous. Tunnel construction is enormously expensive because of the specialized machinery necessary, the geographic conditions present, the safety measures required, the intricate engineering needed, the location and long-term maintenance.
Witness the Chunnel, the channel tunnel that connects the United Kingdom and France, which cost billions of dollars to build, and the Big Dig in Boston, which took years longer than planned and experienced significant cost overruns.
If tunneling were cost-effective, Interstate 24 would have gone through Missionary Ridge instead of around and over it on what is known today as The Ridge Cut. And planners might be well into the design phase of another interstate bypass project that links I-24 in southeastern Tennessee through a tunnel in Lookout Mountain to a link with I-75 in northern Georgia.