10. How many traffic lights are in Manhattan?

Let's say that 150th street is the northernmost barrier for what we will call Manhattan.
We know that there are 12 Avenues going across.
We know that Central Park runs from approximately 59th to 110th street and eliminates 3 avenues across with a lovely park.
We know that below 1st street is an indeterminate number of streets (unless one has memorized maps or works in transportation).
So if we have to estimate the number of traffic lights in Manhattan, we first have to estimate the number of intersections and we know some intersections have stop signs not traffic lights. We also know that an intersection with traffic lights will have at least 8 traffic lights but some times as many as 16 individual traffic lights.
The question was not how many intersections but how many traffic lights.
If we have approximately 3000 intersections and 2/3 of those have lights and 1/3 do not but have stop signs (we simply know that not all intersections have traffic lights)....
And if 2000 intersections have an average of 12 traffic lights, then the approximate number of traffic lights in Manhattan is 24,000.