For the 25th Dutch TT in 1955, the specially constructed 7.7 km race track was taken into use, and this new track also meant that sidecars could be added to the programme. The track that was built in 1955 underwent a complete renovation in 1984. By shortening the North loop the length was reduced by 1.5 km, to a total of 6.1 km. In 1989 the facilities were completely updated and expanded significantly, and with the addition of 3 metres, the width of the track increased to 10 metres.
Source: MotoGP.com – Read Full Article Here