If it increased usage, and one did not invest in more rolling stock, you would just replace rationing by price with rationing by queue. (Think hospital waiting lists, which are endless precisely because they are rationing by queue rather than price.)
That the advantage is very unevenly distributed is also a reason not to have free public transport. (And the payment-by-rates idea strikes me as messy and hit-and-miss in a narrower way. Rates probably already reflect access to the network, as do rents, so it is reasonable to add in a usage charge.)
Experience around the world suggests that about 10% of journeys being on public transport is all one can expect, particularly given such a small percentage of jobs nowadays are where the public transport goes to. Add in the carrying-inconvenience, the small-child inconvenience and the personal security issues to the coverage-inconvenience and I doubt that the effect can be made worth the cost.
Ration by queue
That the advantage is very unevenly distributed is also a reason not to have free public transport. (And the payment-by-rates idea strikes me as messy and hit-and-miss in a narrower way. Rates probably already reflect access to the network, as do rents, so it is reasonable to add in a usage charge.)
Experience around the world suggests that about 10% of journeys being on public transport is all one can expect, particularly given such a small percentage of jobs nowadays are where the public transport goes to. Add in the carrying-inconvenience, the small-child inconvenience and the personal security issues to the coverage-inconvenience and I doubt that the effect can be made worth the cost.