Simply wouldn&#x27;t work - each train has a driver and a conductor, the driver does not interact with passengers at all (and for safety reasons, probably shouldn&#x27;t), while the conductor can only oversee his&#x2F;her immediate surroundings.<p>The issue goes beyond simply wheelchair-bound passengers, but also the fact that the elderly also ride the trains. There are a large number of people who aren&#x27;t fully disabled but for whom having a seat is important, so it&#x27;s not enough to simply reserve a few places for a few individuals.<p>The 4&#x2F;5&#x2F;6 trains are a clusterfuck because they&#x27;re vastly oversubscribed. The serve the entirety of the Bronx <i>and</i> the hyper-dense Upper East Side, not to mention the entire east side of Manhattan. The solution to this isn&#x27;t &quot;leave a large demographic of riders in the cold to gain marginal capacity&quot;, the solution is &quot;build the f&#x27;ing 2nd Ave subway&quot;.<p>There are a large category of improvements to the subway that, while valuable, offer only marginal improvements to capacity. Open-gangway trains can increase per-train passenger capacity by ~5%. CBTC digital train signaling upgrades will get you ~10-20% more capacity by packing trains closer to each other safely. Even stacking a bunch of these improvements together will not resolve the massive capacity deficit the MTA suffers from system-wide. Only new track, new trains, and new stations will.<p>IMO standing-room-only cars fit in this category. It <i>would</i> give us a bit more capacity, but nowhere near enough to make a real dent on the capacity problem - and this particular &quot;improvement&quot; has a high cost in excluded passengers.<p>Even if we made all the cars standing room only, you&#x27;d <i>still</i> be packed like sardines into the 4&#x2F;5&#x2F;6 in the morning, and you&#x27;d <i>still</i> have to watch helplessly as multiple trains pass by packed to the brim.