CJAD has learned that Vaudreaul-Hudson line has experienced more than double the number of recorded delays and cancellations than any other line in the AMT.
That's the result of an Access to Information request for the AMT's incident reports for 2010, which took more than two years to obtain.
The West Island's commuter train line also has had the worst punctuality record in the entire system for the past four years running, according to the AMT's public reports.
According to AMT numbers, this track record continues today.
"They just confirm what we've felt all along" says Clifford Lincoln, one of the co-founders of the Train de l'Ouest coalition, which have been pushing for better service for the West Island.
"We are always in the sidelines when it comes to trains. The improvements are very slow in coming. The money isn't there," he says.
Incident reports from the Vaudreuil-Hudson line list 447 delays and cancellations for 2010.
The second-most problematic line was Deux-Montagne, which reported less than half those numbers, with just 204 incidents. The most dependable line was Mont-Saint-Hillaire. It produced reports for only 76 cancellations and delays.
According to the AMT's public figures, the situation appears to have gotten slightly worse since 2010.
During the period dating back to CJAD's documents, the Vaudreuil-Hudson line was posting a punctuality rate of 94.7%, according to a 2011 report on the AMT's operational budget.
By 2012, that rate had dipped to 94.4%. Today, that number is at a four-year low of 91.9%, though the rail lines have been undergoing repairs.
These are the worst punctuality rates for any line for the past four years, from 2009 until 2012. The average rate is 96.3%.
"We always seem to suffer. In every possible comparison, we always seem to be left out," says Lincoln.
"We've just been stuck for years now fighting and fighting for things that are so possible to be done."
According to the 2010 incident reports, the vast majority of delays and breakdowns on the Vaudreuil-Hudson line were caused by mechanical problems with the locomotives and cars.
Problems with signals and obstructions on the lines were the second most common issue.
The AMT points out that the West Island bound service has undergone a number of upgrades since 2010, and that work is currently being done.
"We now have new multi-level cars and are undergoing repairs on the rented rolling material," the AMT's communications councillor said in a written email.
Claudia Martin, however, would not answer further questions about why Vaudreuil-Hudson has been dogged with the worst track record for the past four years.
She says talking about the 2010 incident reports and the track record for the West Island service would be confusing to the public and would not be useful to the AMT.
"We reiterate that we will not go forward, under any circumstances, with an interview concerning the statistics of the passed years," Martin wrote to CJAD.
Lincoln, however, says the West Island-bound line handles more freight traffic, and the added repairs that are needed as a result take place during the day, rather than at night when the work would have no impact.
Improvements to deal with signalling problems have been slow, he says, and the need for a third track is "urgent".
"They (the statistics) show incontrovertible proof that we are behind. We are losing on every area of comparison."