most navigated river

I googled which river had the most traffic and which was the busiest. Each time the Yangtze River came up.

The problem to find such a list is in my opinion the combination of "river" and "navigate".
Usually, such lists are about "waterways" since waterway is any navigable body of water.
Rivers are navigable, - if navigable.

The Rhine is the busiest navigable river of the world, the Kiel Canal is the world's busiest man-made water- way navigable by seagoing ships.
And the you've got "systems", like the Great Lakes, the Yangtze River system ... ...