As part of these negotiations, Switzerland offered to build a high-speed rail link through the Alps for intermodal freight transport. Swiss voters approved the link in a 27 September 1992 mandatory referendum. The EU accepted the Swiss offer in 2000, but asked that the extant 28-tonne weight limit for lorries be raised to 48 tonnes. The parties eventually compromised on a 40-tonne weight limit. The bilateral Land Transport Agreement with the European Union was signed, agreeing to an increase of the kilometer-based tax (HVF; , , ) on HGVs from 1.6 ct/tkm to 1.8 ct/tkm when the NRLA was completed. The condition was deemed fulfilled at the completion of the first track of the Lötschberg Base Tunnel in 2007.