I tracked the first section of the line Maastricht to Lanaken in my 2006. In 2013 I went back for the final visit Lanaken to Bilzen.
The railway was opened in 1856 as to connect Maastricht to the Belgian city of Hasselt and more important the Belgian rail network.
From 1867 the train services were taken over by the company Grand Central Belge. In 1900 the GCB was taken over by the state (of Belgium).
The construction of the Albert canal in the thirties meant the railway traject had to be shifted and a new bridge was build.
In 1951 the passenger traffic on the line came to an end.
In 1990 the dutch part of the line was taken out of service and in 1992 the Belgian part followed. The last international freight train using the railway was a train transporting coal from the German coalmine in Merkstein to the cokes factory in Zolder, Belgium.
There are several plans to reopen the line. On plan speaks about reopening it for the industry in the area, but other plans are talking about a lightrail system connecting Maastricht to Hasselt.
Update 2013: The railway was reopened for freight traffic between 2009-2011. The first freight train drove the tracks again in 2011. The spartacusplan for public transport in the Belgian province of Limburg forsees a railway connection between Hasselt and Maastricht in 2018. We'll see about that.