I think you need to indicate whom will the sustainability be measured? The human society or the natural world or a combination of both. It maybe impossible when we take away land from nature to grow our cultivated crops and domesticate animals, plus the need for forestry products cut down faster than they can grow, for the current population level to become sustainable? I Ask AI suggests we need to have a one billion reduction in the world human population to become long-term sustainable.

Dear Craig Carlton Dremann the updated question is How Urban Transport Sustainability can be measured?

Once again, urban transport sustainability is just a smaller subset of overall human population sustainability in relationship to its surroundings. Cities are constructed piecemeal, and in the USA were first designed around horses, then 1900s to 1950s around public mass transportation like trains, buses, trollies and the like. Then the gas and auto companies got the public mass transportation eliminated in places, so that individual cars would be the method to get around.

The last streetcars and trolley buses in Los Angeles were scrapped on March 31, 1963. This ended nearly 90 years of streetcar service in the region.