There are a number of modes of public transport in the Greater Dublin area run by a number of transport operators, most of them state or semi-state entities. Public transport in Dublin was overseen by the Dublin Transportation Office until 2009 when the National Transport Authority replaced this body. Public transport in Dublin underwent a major expansion in recent years, and the Irish Government had plans to invest heavily in the system under the Transport 21 plan. However, as a result of the changed economic environment since 2008 these plans have been subject to re-assessment.