| | Madrid Metro http://www.metromadrid.es |
| | Madrid Railway Museum http://www.ffe.es |
| | MAFEX http://www.mafex.org |
| | Magazine international de l´actualité ferroviaire (LE RAIL) http://lerail.free.fr |
| | Maintex http://www.maintex.qc.ca |
| | Manchester Public Transport http://www.gmpte.gov.uk |
| | Massachussets Bay Transit Authority (MBTA) http://www.mbta.com |
| | Mer Mec Spa http://www.mermec.it |
| | Mercurio http://mercurio.iet.unipi.it |
| | Metra´s Commuter Rail System http://www.metrarail.com |
| | Metro de Caracas http://www.metrodecaracas.com.ve |
| | Metro de Santiago http://www.metrosantiago.cl |
| | Metro Valparaíso http://www.merval.cl |
| | Metrofor http://www.metrofor.ce.gov.br |
| | Metrovias http://www.metrovias.com.ar |
| | Ministerio de Transporte de Colombia http://www.mintransporte.gov.co |
| | Ministerio de Transporte de Cuba http://www.transporte.cu |
| | Ministerio de Transportes de Brasil http://www.transportes.gov.br |
| | Ministero dei Trasporti e della Navigazione http://www.trasportinavigazione.it/ |
| | Ministry of Transport (Denmark) http://www.trm.dk |
| | Ministry of Transport (Lithuania) http://www.transp.lt |
| | Ministry of Transport (Slovakia) http://www.telecom.gov.sk/einfomin.html |
| | Ministry of Transport, Canada http://www.tc.gc.ca |
| | Ministry of Transport, France http://www.equipement.gouv.fr |
| | Ministry of Transport, Japan http://www.motnet.go.jp |
| | Ministry of Transport, Netherlands http://www.minvenw.nl |
| | Mobility Fund for Disadvantaged Young People http://www.coe.fr/youth/english/mobilty.htm |
| | Monticello Railway Museum http://www.prairienet.org/mrm/ |
| | Morrocan Railways (ONCF) http://www.oncf.org.ma |
| | Moscow Metro http://www.metro.ru |
| | MotivePower Industries http://www.motivepower.com |
| | MRS http://www.mrs.com.br |
| | MTT http://www.mtt.cl |
| | MTU Friedrichshafen http://www.mtu-friedrichshafen.com |
| | MVA Group http://www.mva-group.com |
