New Delhi, Feb. 23 -- Millions of people in New York City and a large swath of the northeastern U.S. were stuck at home under road travel bans and blizzard warnings on Monday as a fierce winter storm barreled into the densely populated region with heavy snowfall and high winds.

Cellphones across New York City received wailing push alerts Sunday night announcing a ban on non-emergency travel on all streets through noon Monday because of "dangerous blizzard conditions." Rhode Island and New Jersey implemented similar restrictions. Regional airports saw widespread cancellations and delays, and public transit was suspended in some areas. Even DoorDash announced it was suspending deliveries in New York City overnight.

Blizzard warnings stret...