Manhattan’s population expands from its 1.5 million local residents to up to 3.9 million people on weekdays, including 1.6 million commuting workers, 374,000 local day-trip visitors, 70,000 students, 400,000 out-of-town visitors, and 17,000 hospital patients. Altogether, more than 2 million people exit and enter Manhattan around the same time each day – mostly by public transit.

What would it look like if all of those commuters entered Manhattan by car, instead of the 16 percent that currently do? According to highway engineer Matt Taylor, something like this:

Matt Taylor,

Taylor calculated exactly how many bridges and tunnels would be needed for all these vehicles to enter Manhattan within a 4-hour period in the morning and a 4-hour period in the evening. In addition to Manhattan’s current 20 bridges and tunnels, he estimates it would require 48 new 8-lane crossings, which are drawn arbitrarily in the image above. For parking, Taylor estimates just the commuters would need the equivalent of a layer of underground parking under the entire island.

It's an exercise that will definitely make you thankful for public transport.

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