ERP, pay according to usage

Thomas Koshy has some great suggestions in his article on ERP rates in Today. The principle he relies on is that the more one crosses the gantry, the more one pays. And for those who cross more, the rate will also be higher. At the other end, I like this best, is infrequent users will be given a kind of waiver for the first time they cross a gantry. The fees not collected is compensated from the high users. As for those in the transport business and need to transport goods and people, try to use buses and MRT to save on paying more ERP charges. And for those unfortunate poor buggers whose travel patterns require them to cross ERP frequently, or have an ERP outside their homes, maybe they can introduce something like a frequent travellers or mileage rewards like what the airlines are doing. Very interesting suggestions, the same principle as using water. The lesser water people used the better. The lesser people use the roads, the better. Why do we need to build roads and rails?