New York's commuter nightmare is bad, but the world's most crowded cities are even worse

Over the past several months, multiple delays have led to crowded platforms where hordes of sweaty bodies squeeze together. An overworked subway system is to blame.

The same is happening around the world, and on a far more concerning scale. By the year 2050, 70% of the world will live in cities, according to the Population Reference Bureau.

The most population-dense cities grapple with unique challenges. They fight for resources, like housing and personal space, and they put infrastructure to the test.

Here's just a taste of what life is like.

New York City is the densest city in the US. One square mile contains more than 27,000 people, and it's led to countless delays for commuters. But claustrophobic as it may seem, it barely stacks up against the world's most crowded cities.

Source: NYC Population

Consider Manila. With a population density of 107,000 people per square mile, it's the most crowded city in the world.

Manila's fertility rate is 3.1 children per woman. Experts predict the population will double by 2025, despite fears the city's infrastructure can't sustain the boom.

Source: World Population Review

Transportation is the most visible casualty of overcrowding. In Kolkata, India — pop. density: 63,000 — monsoon season threatens service on already-congested highways.

In matters of housing, too, Kolkata residents often shack up with the inventory they'll use throughout the day. Here, a tricycle puller brushes his teeth in the garage used to house his bikes.

Kolkata is far from India's densest city; Mumbai's 73,000 people per square mile forces homes to shrink to unthinkably small sizes.

The rent for a 100-square-foot home ranges from $0.04 per square foot to $0.06 per square foot.

In Hong Kong's densest cities, entire families live in 60-square-foot micro-apartments that still cost nearly $500 a month.

Source: Business Insider

So-called "cubicle homes" (or more ominously "coffin homes") house older individuals who may not be able to afford more space and have no family to take them in.

In Dhaka, Bangladesh — pop. density: 73,000 — trains are so crowded that commuters will jump between cars when one pulls into a transfer station.

Elsewhere in the city's markets, vendors pile in to accommodate the thousands of visitors looking to buy vegetables, mosquito nets, and freshly-slaughtered livestock.

Israel's densest city, Bnei Brak, has a population density just north of 70,000 people per square mile. Political rallies and holiday celebrations see the largest outpouring of residents into public spaces.

It contains many large Orthodox families as well as inhabitants who have moved from smaller neighboring cities.

In that regard, crowded cities can also fuel joyous celebrations like rural towns never can. In New Delhi, India, tens of thousands took to the streets in March to celebrate the poll results of the high-ranking politician Amit Shah.

Supporters danced, played music, and showered one another with brightly-colored powders in celebration.

And in the entertainment hub of Macau, a city with a population density approaching 55,000 people per square mile, the closeness has made for electric celebrations — on par with the caliber of Las Vegas.

The city's overwhelming density highlights how wealth (or lack thereof) can turn density into either a public-health concern or a lucrative financial opportunity ready to be seized.

It almost makes New York City look quaint by comparison. Almost.