It’s complicated. The Overlook Walk would be a kind of land bridge over the cliff — a deck and pathway of varying widths and slopes, including one bridge span, all laid atop three large new buildings. Taking off from MarketFront, the year-old addition to Pike Place Market, it would land with branching stairways on a plaza in front of Pier 59 (the Seattle Aquarium) and Pier 62.

While the new street system takes cars past the waterfront, the Overlook Walk points over streets to the water, the mountains, the Seattle Aquarium and the historic piers.

No traffic would have to be negotiated because by the time it’s built, the main trunk of a re-built Alaskan Way — Elliott Way — would be underneath it, heading up the cliff, on the footprint of the old viaduct, to Belltown. A slimmer Alaskan Way would turn back again toward the water and follow the shoreline, as it does now.

I told you it was complicated, and it’s not exactly a done deal.

About $200 million of the $688 million price of the rebuilt Seattle Waterfront is to come from a local improvement district, a contentious plan for assessing downtown property owners now awaiting Seattle City Council approval.

The design team is led by James Corner Field Operations, under the City of Seattle Office of the Waterfront. Environmental impact has been assessed and many public outreach events have been held since design began in 2012. Adjustments and refinements have been made. The Overlook Walk is likely to be approved by the Seattle Design Commission after one more review at a not-yet-announced time.

Look for the viaduct to be dismantled next year. After that, work on the roadways and the Overlook Walk structures would begin. If it moves forward, the whole thing should be completed by 2023, in tandem with the Seattle Aquarium’s new Ocean Pavilion, an exhibit building that would tie in with the Overlook Walk in a new plaza along the shore.

The basic job of the Overlook Walk is outrageously ambitious: to connect the urban shore — long cut off by our aerial highway — to the city. When it comes to transforming the waterfront, this is the big move. It’s not perfect. It’s not magic. And it’s definitely not even well known or understood, despite all the process. So how do we know it’ll be good?

One reason is that design success is based not on learned civic behavior, but on basic instincts, tested and proven. People like to walk in high, open places. Every outdoorsy Seattleite knows that. It’s true in the city, too. Discovered views attract them like a magnet.

That’s how the Overlook Walk would work. It would be Seattle’s best shot at a wide-open walkway with stunning views of the city, water and mountains.