First of all, you never have it to yourself. Although the car traffic is on a lower level on either side of the pedestrian path so you have unimpeded views on both sides, the walkway itself is narrow and it's full of walkers, bikers, and lots and lots of tourists.
Then there's this.
The walkway is a little longer than a mile, but once you're actually on the bridge, the pavement gives way to wooden slats. And you can see the East River, far below, between the slats. The bridge underwent a complete renovation just a few years ago, so I suppose it's safe.
But it doesn't feel safe. It had probably been at least ten years since I'd crossed, and though I remembered that I didn't like it, I'd forgotten exactly how much. I really wanted to take pictures, so I gritted my teeth and tried not to look down, but my knees were literally wobbling until I was safely back on Manhattan asphalt.