Bridge vs Tunnel

Just a thought. What is they built a bridge to Penn Station in New York rather than a tunnel. Here is the result. First for a tunnel, I have used the average estimates from various sources:

	Tunnel
Amount	$20,000,000,000
Duration	40
Interest	4.00%
Passengers per day	600,000
Passenger days	156,000,000
Fee per Trip	$6.48
Annual Bond Payment	$1,010,469,786

Then for a bridge. I assume that one just duplicates the Tappan Zee Bridge.

	Bridge
Amount	$4,000,000,000
Duration	40
Interest	4.00%
Passengers per day	600,000
Passenger days	156,000,000
Fee per Trip	$1.30
Annual Bond Payment	$202,093,957

Thus for a $1.30 a trip we can get a bridge in about 3 years! So what is the problem?