Too many factors not allowed for, and no control groups. Perhaps merely going into Manhattan raises stress levels. How do these stress levels compare to stress levels of those who drive in? Of those who drive into or take a train into other large cities? Crowds trigger panic attacks in some people that suffer from depression, and though I've never had a panic attack, I've been greatly stressed off and on by croweds -- I know two people who _can't_ shop at Walmart because it triggers an actual panic attack. ("Panic attack" is a technical term here: they most resemble a heart attack, and sometimes can be confused with one.) I never let political views interfere with my relation to commodities, but I never shop at Walmart because I too am somewhat affected by crowds. I stopped shopping at Kohls for the same reason -- narrow aisles and lots of people.
In any case, Nothing useful can be said about the relation of X to stress unless X is carefully compared to Y, Z, P, Q, R, XX, YY, PP, QQ, RR, ......NN.
[WS:] Absolutely. Everything in life is stressful, so the real question is the relative level of stress. Driving is associated with extremely high stress, as illustrated for example for the number of articles on the subject fund by googling driving+stress. I know many otherwise normal people who experienced acute panic attacks while driving.
For me the most stressful aspect of driving and car ownership in general is not the mechanics of driving - which I find quite boring and soporific - but the constant awareness of being a prey to a wide variety of rackets - from the so called "law enforcement" (hefty fines for crossing arbitrary lines drawn by state bureaucrats and cops, arbitrary pullovers, searches and seizures, insurance racket, parking racket, towing racket, etc.) to plain old fashioned crimes (e.g. breaking a $300 window to steal a $5 phone charger.)
I find it quite ironic that an average motorist in the supposedly "free" Amerika is subjected to more everyday surveillance than an average citizen in supposedly "totalitarian" communist countries of Eastern Europe.
Wojtek