Commuter is the brand name given to the suburban rail services operated by Iarnród Éireann in Ireland. These operate in and around the suburban rail networks of Dublin, Cork, Limerick and Galway, in contrast to the majority of services which are classed as InterCity. In recent years, Iarnród Éireann has put a significant amount of effort into upgrading its network, with new tracks, signalling, station upgrades and trains. The majority of Commuter services are operated by diesel multiple unit train sets. An exception to this is the DART service - this shares the line with several other services. It is the only electrified heavy rail service in Ireland.