http://www.cbc.ca/canada/montreal/story/2010/08/31/mtl-negro-centre.html

just think how hot your car gets in the sun with the windows closed

I’ve never had a car, but I’m familiar with the phenomenon.

Obviously I have no statistics or expertise, but it seems to me anything that gets people to stop using their cars is a good thing, no?

Things can certainly be done to the new trains to allow a future installation of an air-conditioning unit. But there is not a lot of room on the train to install these bulky units.

The STM is already working on the problem of overheating in the metro. For example, they are building a new ventilation tunnel near Jean-Talon metro:
http://www.stm.info/info/infostm/2010/100804.pdf
The best that can be achieved with this approach is to bring the temperature of the tunnels and stations to the outside air temperature.

To my knowledge, the metro is not heated. There are heaters in the cars but I don’t think that they are turned on. The heat in the stations/trains can come from: the passengers themselves, the brake shoes after friction braking, the tires from the rolling resistance, and the inefficiency losses of the traction motors.
For trains that run outside, a major source of heat is solar radiation (just think how hot your car gets in the sun with the windows closed). Luckily Montreal’s metro does not have to deal with this problem.

Adding an air-conditioner to the train would just add an extra source of heat to the tunnels and stations. People would then naturally call for installing air-conditioning in the stations. In order for air-conditioning in the stations to work, the STM would likely need to install platform screen doors (http://en.wikipedia.org/wiki/Platform_screen_doors) so that the station area can be efficiently air-conditioned without having the cold air escape into the tunnels and then out the ventilation shafts.

Air-conditioning the trains would therefore likely result in a cascade of major retrofit costs to the entire network.

London has had this problem for many years and there is even a web site about it:
http://undergroundcooling.co.uk/

I think if we want a metro system that can bridge to the outside – notably to flatter sections of the city to the east and west of the central plateau / escarpment – the best and easiest solution is to create intermodal stations where you can change from Metro to light rail. We could create a few lines that run along existing highways (20, 40/Met, Decarie, Cote-de-Liesse), with stops and hubs connecting existing Metros with commuter rail; maybe if we teamed up via the AMT, this could become a single network for Montreal, Laval and the South Shore (also at a cost savings). Frankly, we need something like the NYC subway-rail infrastructure to tie things together more seamlessly.

This whole thing is urban legend: the snow isn’t inherently a serious problem for rubber tires if they are designed appropriately. The same legend comes back in reference to streetcars/trams running on our roads with steel wheels. Cars, buses, and trucks seem to manage reasonably well even without rails.

It’s really so very simple why the Montreal Metro runs entirely underground: It’s the trains and the rails, not the wheels. The trains aren’t weatherproof, and precipitation would cause problems with the third rails.

Not to mention, ZEL was right to say that today’s steel wheel technologies can achieve the same grades and turn radii as rubber tired sets. However, they can’t do them as quickly or as quietly. Imagine how screechingly noisy and S-L-O-W the tunnel between Champ-de-Mars and Berri-UQÀM would be??? Plus…knowing that there are shale deposits in our bedrock, I’d imagine the vibrations could cause some problems…

etc. etc. etc. ZEL is a scheister and a bully, plain and simple. They would have left us with a big bill and without a usable metro for years and years.

Rubber-tired metros can run outdoors, actually. I think the main problem with that on our system would be the way the third rail is set up, but that’s another story.

I agree it’s slightly nerve-wracking to think about the suspension of service necessary if the metro system were to be rejigged for rail, but what if it meant long-term savings over the following decades?

Place a bad bet on a stadium roof and you have a leaky white elephant. Lose out when letting an inexperienced firm rip up your metro system, and you have hundreds of thousands of people riding buses until the STM and ZEL are done suing each other.