What is wrong with simply extending the O-Train service to the proposed Light Rail corridor? When the service reaches the capacity later, the line could be double-tracked. The significant left-over money from the federal and provincial governments could be used for setting up the East-West line with diesel-powered trains, just as the O-Train was originally set up very economically.
The critics have argued about the noxious fumes from diesel engines, which is true today. However, the O-Train may already use bio-diesel fuels which are said to be environmentally friendly. I do not mind smelling French fries and donuts on the train. Do local restaurants mind donating the used-up frying oils to the O-Train? Is there anybody who is allergic to the scent of French fries and donuts? :-)
Buses powered by hybrid diesel-electric engines already exist (even in Gatineau, QC, as of 2007). Therefore, newer O-Train could be powered by hybrid diesel-electric engines with bio-diesel fuels, making the O-Train even more environmentally friendly and also allowing the O-Train to pass through tunnels and enclosed areas without emitting exhaust fumes.
When fuel cells become more reliable and economically feasible, the O-Train could switch to all-electric motors powered by dihydrogen (H2) fuel cells whose exhaust gas is harmless dihydrogen monoxide (H2O). Thus, electrification with overhead catenary wire lines would not be necessary at all. The overhead catenary wire lines are not only costly but also are prone to damage by freezing rain and ice storms.
Eventually, fuel cells could power all buses, too.
