> And an excellent system involves collecting fare revenue from riders. This is far from self-evident. There are at least two ways to fund such a system (and v

> And an excellent system involves collecting fare revenue from riders. This is far from self-evident. There are at least two ways to fund such a system (and variants within), and most systems are funded by a combination of taxes and user-fees. Unlike roads, which are usually free at point of use, and this model should probably be applied much more often to public transport if we are to wean ourselves off driving everywhere. > The answer is that you’re not spending it to halt X, you’re spending it to halt 10X down the road. You need to justify this somehow to justify spending X > Y on enforcement. This is very far from self-evident, and my hunch is that these numbers are either relatively stable, or correlate with economic 'health' of the community, which is to suggest that the 'network effect' doesn't apply here as you suggest. Your enforcers will not be (anywhere near) 100% effective either. At best, maybe you can expect to break even, but even that is probably difficult, and since 'breaking even' means significant negative impact on individuals, and has serious risk of scope creep and perception issues with the 'transit cops', it doesn't sound at all worth it. What happens when someone gets caught dodging the fare and fined? They can't afford to pay the transit fare, and now they can't afford a fine that is, what, 20X the fare, and it just adds to their stress / debt load / collections coming after them. Meanwhile, since they can't afford it, they don't pay it, and the city doesn't actually collect any revenue from this endeavour. This is like library fines - the people who most need the system either get excluded from it or it even starts actively working against them. Unless the system is running into capacity limits (or capacity break points), the marginal cost of freeloaders using the system is effectively zero; the trains run anyway. The ROI on paying for enforcement is almost certainly going to be terrible. It's very reactionary 'wrongdoers should be punished' thinking that doesn't actually solve anything. Remember that governemnt services like public transit shouldn't be operated like for-profit businesess. The product of their efforts, and the way to judge them, is people transported, not dollars.