What is the most durable way to paint a wood floor in a high traffic area?
The success of the paint job very much depends on the nature of the traffic. 

If it is accessed with road shoes, the sand on the shoes will quickly sand down any kind of paint. In case, I would go for clear boat paint and put a mat over the traffic area. In case you want to go without a mat, go for a satin or matte finish paint. That way, the wear doesnt show as much. 

If it is mostly accessed with clean (indoor) shoes, you can go for a number of good floor paints. I´ve had success both with a water based lacquer and a wax based open pore treatment.