Where are you from? Do you know how it's like sitting in the traffic jam everyday?
You are aware that all his plan for the tunnel would do is move the traffic jam to the tunnel entrance?
Do you know the best form of an entrance to a tunnel? An opening that connects directly to the road that cars continue to drive along.
Do you know what that is called? A tunnel.
Elon's addition to the tunnel is nothing more than pure stupidity.
Digging a bunch more tunnels may help with traffic to some extent.
But tunnels already exist.
Also, given the choice I would prefer to sit in a traffic jam in the open air rather than in a tunnel.