I don't buy those studies, or rather the conclusions others derive from them. Most people do just fine with longitudinal seating on a train. Only a very small minority of people have chronic ailments that would affect their ability to sit longitudinally and/or get motion sickness on trains. Anecdotally, I have been thrown out of transverse bus and train seats during hard braking. I stumbled forward and landed standing on my feet, but AFAIK I don't have any chronic ailments. I would think Grammy Edna, with her vertigo and high blood pressure, wouldn't take getting thrown onto the hard floor well.
If you ever get to ride a subway that is operated with some fervour, unlike the Line 1 sunday driving experience, you'll know what I am talking about.
Motion sickness on a boat, bus or car is an everyday risk for many, but on a train, come on man, the chances are much lower. If they can survive walking onto the subway train, they can survive sitting longitudinally for a few minutes to an hour. Elderly people in my family who always get carsick never get motion sick on the subway. Throwing the baby out with the bath water to help them feel a bit more comfortable leads to a net loss for society.
This mentality that we should sacrifice the economics and thereby the derived social benefits of a rapid transit system in pursuit of maximizing comfort, far down the list of priorities is frankly ridiculous. This usually only comes from people privileged enough to avoid crowded transit, privileged enough to avoid crush load subway cars, privileged enough to not be living in a developing country. *cough* *city council* *cough* *Metrolinx execs*. Not to mention it goes against global best practices. Transverse seating only makes sense for transit where the load factor during most of the day is low. For a serious transit line like the REM, which is supposed to be Montreal's regional backbone and absorb decades of ridership growth on <80 metre trains, it absolutely makes no sense. It is a travesty that the fast and frequent Ontario line will be plagued by regressive, antiquated transverse seating. That is despite having a much higher load factor and ridership projection than the REM. Those saying otherwise reveal an unworldly mindset and lack of understanding how serious metro systems work.