for example the estimated total investment costs necessary to achieve the transport masterplan targets including road and public transport targets by for ha noi and ho chi minh city are about usd billion and usd billion respectively adb viet nam is not alone in facing a funding gap when it comes to infrastructure development according to the addis ababa action agenda the infrastructure funding gap in developing countries can be estimated to between usd and trillion united nations however considering the clear resource gap viet nam urgently needs to devise complementary funding strategies one of these mechanisms as highlighted above could be to price against negative externalities of car usage through congestion and parking charges and redirect this revenue into public transport infrastructure development