Open invitation to tender, deadline 07.05.2013, for retrofitting, refurbishment and adaptation of operational features of Ems BAB31 tunnels. Further information, specs and docs from Herrn Campe at NLStBV in Oldenburg, tel +49 441218-10, fax –1222, e-mail Postelle@nlstbv-ol.niedersachsen.de to whom tenders or requests to participate must be sent. Time limit for access to documents 30.04.2013. Visit http://ted.europa.eu/udl?request=Seek-Deliver&language=en&docid=099886-2013. NUTS code DE94C. 13/13.