MisterF, calling the replacement of streetcars with buses the world over a "failure" would be very hard to assert, considering that the majority of cities the world over dumped their streetcars for buses, or higher order rail transit, nearly fifty years ago and, in some cases, almost a hundred years ago. Don't forget, it's not just NA cities that abandoned trolley networks, practically every city outside of Central and Eastern Europe ripped up their tracks during this time.
Many of these cities, particularly in Western Europe, didn't dump their streetcars because of "GM conspiracies" or to acquiesce to private automobiles - it was simply more advantageous to run buses over streetcars because of the inherent deficiencies of running and maintaining street railways.