When you say "common," can you be more specific? I believe the actual rate, in the form of trips with an incident over trips without an incident, would be described as extremely uncommon. Perhaps there's been an uptick, and perhaps it's even more common in NY than other large cities, but probably less common than being a victim of similarly bad circumstances (plus collision risk) inside a car.
There are severe crimes reported weekly this year - you can simply just check the news for that along with regular assaults and hundreds of harassment cases. I am not sure I would quantify the rate as "extremely uncommon".
This got me double checking myself, but it does seem that a typical "common versus rare" threshold is a rate of 5%, though other values like 1% and 10% are sometimes used. Based on this, I'll concede that it might be common for an incident to make the daily news (if there's one a week, so 1/7 chance) but I stand by my claim that trips with such incidents are extremely uncommon relative to all trips.
There's 8 million+ people in NYC. So even if there are 8 severe crimes in a period of time that is still a one in a million chance. Seems extremely uncommon to me. Though I do agree, the uptick in crime is not great.
The last few years have shown that even if something is extremely uncommon you've still got to move heaven and earth to stop it happening. Costs be damned.
Metal detectors at every station entrance , mental health screening prior to boarding perhaps?
