Why might a city planner want to know how many bicycles are on the streets, how fast they’re going, and in what direction they’re moving?

There are lots of reasons why, says Austin Ashe, general manager for intelligent cities at Current, a General Electric subsidiary. “By time stamping and aggregating the data, we can find out what parts of a city are used most and least by bicyclists, and [consider] what the city can do to enhance ridership or make existing areas that riders use more safe.”

“You can also see how this data could be used by bike share applications,” he said, “or integrated into traffic signals, for example, giving bicycles a protected left turn.”

Current designed and installed the City of San Diego’s 3,200 smart streetlights, each of which monitors roughly 36 by 54 meters of pavement. The network, which became operational in 2018, initially tracked only cars, both on the move and in parking spaces, and started using that data to place stop signs and time traffic signals.

San Diego then added data about pedestrian movements into the mix. And, in the second quarter of this year, the city updated its network to count bicycles and record their movements as well.

Developers used machine learning, Ashe said, to teach the system to “distinguish a bike from a car, a person, or a trash can.” It wasn’t the simplest of projects, he indicated, with “a lot of edge cases,” and complicated by the position of the sensors way up on lampposts—bicycles are far more distinctive when viewed from the side than from above.

Standard image analytics, Ashe said, “didn’t let us count ‘cyclists,’ rather we had to count what the classifier can detect, which is one bicycle and one person. Then we further analyzed these two data sets into an ‘insight,’ inferring that when a bicycle and a pedestrian are reported with the same location and the same time stamp, then they are some percentage likely to be a cyclist.”

Once the system is trained, the actual processing of what is and isn’t a bike takes place “at the edge”—meaning, in the streetlights themselves.

The developers who worked on the bike-counting software discovered a surprising glitch during real-world testing: the system was counting some bicycles that were actually not being ridden—for example, those hanging from bike racks on public buses, or tossed into the beds of pickup trucks.

The software has the same problem when counting pedestrians, Ashe said. “If a car drives by that is a convertible, we are counting it as both a car and a pedestrian, even though the ‘pedestrian’ is the driver.”

“Our next challenge is to fix that,” he said.

After the developers perfect the sensor network’s ability to count bicycles, Ashe isn’t sure what will come next. Perhaps, he says, the streetlights will start counting scooters, or shopping carts, or wheelchairs—data on any of these items would be useful from a city planner’s view.

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The Spectacular Collapse of CryptoKitties, the First Big Blockchain Game

A cautionary tale of NFTs, Ethereum, and cryptocurrency security

8 min read
Mountains and cresting waves made of cartoon cats and large green coins.
Frank Stockton

On 4 September 2018, someone known only as Rabono bought an angry cartoon cat named Dragon for 600 ether—an amount of Ethereum cryptocurrency worth about US $170,000 at the time, or $745,000 at the cryptocurrency’s value in July 2022.

It was by far the highest transaction yet for a nonfungible token (NFT), the then-new concept of a unique digital asset. And it was a headline-grabbing opportunity for CryptoKitties, the world’s first blockchain gaming hit. But the sky-high transaction obscured a more difficult truth: CryptoKitties was dying, and it had been for some time.

The launch of CryptoKitties drove up the value of Ether and the number of transactions on its blockchain. Even as the game's transaction volume plummeted, the number of Ethereum transactions continued to rise, possibly because of the arrival of multiple copycat NFT games.

That perhaps unrealistic wish becomes impossible once the downward spiral begins. Players, feeling no other attachment to the game than growing an investment, quickly flee and don’t return.

Whereas some blockchain games have seemingly ignored the perils of CryptoKitties’ quick growth and long decline, others have learned from the strain it placed on the Ethereum network. Most blockchain games now use a sidechain, a blockchain that exists independently but connects to another, more prominent “parent” blockchain. The chains are connected by a bridge that facilitates the transfer of tokens between each chain. This prevents a rise in fees on the primary blockchain, as all game activity occurs on the sidechain.

Yet even this new strategy comes with problems, because sidechains are proving to be less secure than the parent blockchain. An attack on Ronin, the sidechain used by Axie Infinity, let the hackers get away with the equivalent of $600 million. Polygon, another sidechain often used by blockchain games, had to patch an exploit that put $850 million at risk and pay a bug bounty of $2 million to the hacker who spotted the issue. Players who own NFTs on a sidechain are now warily eyeing its security.

Remember Dragon

The cryptocurrency wallet that owns the near million dollar kitten Dragon now holds barely 30 dollars’ worth of ether and hasn’t traded in NFTs for years. Wallets are anonymous, so it’s possible the person behind the wallet moved on to another. Still, it’s hard not to see the wallet’s inactivity as a sign that, for Rabono, the fun didn’t last.

Whether blockchain games and NFTs shoot to the moon or fall to zero, Bladon remains proud of what CryptoKitties accomplished and hopeful it nudged the blockchain industry in a more approachable direction.

“Before CryptoKitties, if you were to say ‘blockchain,’ everyone would have assumed you’re talking about cryptocurrency,” says Bladon. “What I’m proudest of is that it was something genuinely novel. There was real technical innovation, and seemingly, a real culture impact.”

This article was corrected on 11 August 2022 to give the correct date of Bryce Bladon's departure from Dapper Labs.

This article appears in the September 2022 print issue as “The Spectacular Collapse of CryptoKitties.”

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