Tom Vanderbilt's Traffic: Why We Drive the Way We Do (and What It Says About Us) contains the same conclusion that late merging leads to less congestion because of fuller utilization of available lanes. Related reasoning supports the London Underground's Holborn Station experiment to encourage escalator users to stand on both sides, rather than the customary stand-to-the-right, walk-to-the-left.
https://www.amazon.com/dp/0307277194
https://www.nytimes.com/2016/06/13/world/europe/a-london-sub...