This was a very interesting article. I always find experiments involving honor systems very fascinating. The bus system in Germany and some parts of the Boston T (the trolleys when they are overground) are basically honor systems. In Bonn, Germany people are very particular about paying the fare. In Boston, not so much.
Rome has(had?) an honour system for public transport too. We didn't realise that no one ever pays unless they see inspectors getting on the bus. Lots of people would leap up and punch their biglietti when we punched ours because they assumed we had seen some inspectors. I couldn't work out what was going on until I read about it in the Time Out guide which explained that almost no one pays :-)
London had exactly the same system and the same fare evasion problem on the high traffic bendy bus routes. These routes were always overcrowded probably because of the number of unrecorded passengers using them. They withdrew these buses and replaced them with ones which take longer to board partly because of the fare evasion and partly because a sort of bizarre bus xenophobia (hatred of a foreign european style of bus) inspired by the Evening Standard which resulted in an election promise by mayor Boris to get rid of them.
I can't speak for their motivation, but the what the Evening Standard (and Metro et al) printed was not related to the origins of the bus. They claimed they were dangerous to other road users. TfL disputes this.
Solving the overcrowding issue is more complicated than building higher capacity buses - you have to think about the speed of boarding, route layout, speed of navigating London's congested streets, fare evasion and more. In some places, the bus stops allow for two bendy buses or 3-4 regular buses to board at once, which means faster boarding on regular buses during peak times.
The new Routemasters, with 3 doors and 2 staircases, might prove to reduce overcrowding despite their lower capacity.
There was plenty of research behind introducing bendy buses. The main argument being that they transit the route faster overall because they have a much shorter dwell time at stops. The introduction of bendy buses was a rational evidence based decision, the campaign against them was mostly emotional hubris, which resulted in them being replaced early at vast expense to the taxpayer. The main reasonable complaint against them was that you were more likely to have to stand up, but you often couldn't even get on the bus (e.g's routes 73,38) before they were introduced so I don't know what's worse.
We have bendy buses in Birmingham UK (route 66). They seem no less popular than other buses. People enter via front and leave via back so passes must be shown to driver and (exact) fare paid. I shall ride them with pride if Boris does not like them...
When my in-laws first saw the honor based public transport system in Munich/Germany they commented that this would probably not work in their home city Taipei/Taiwan.
Yeah, MUNI(cipal railways) of SF, which uses a kind of honor system for buses and above ground LRVs, have a fare evasion rate of 15 to 30%, based on MTA estimates.
Local activists typically lobby against enforcement as they interpret it as targeting a vulnerable population. On the other hand, MUNI is running a deficit.
