Chasing Away Urban Congestion

By Carmen Nobel  |  Posted 2008-02-21

Last April, in an Earth Day speech at the American Museum of Natural History in New York, Mayor Michael Bloomberg unveiled a sweeping plan to clean up the city and reduce its greenhouse gas emissions. Dubbed PlaNYC, it focused on areas such as housing, water quality and transportation. PlaNYC encompasses more than a hundred initiatives, including a controversial plan for traffic-congestion pricing.

The proposal calls for a per-use fee charged to vehicles that drive through a certain cordon of lower Manhattan during peak traffic hours. The hope is that commuters will consider carpooling or using public transportation to avoid the fee, mitigating both traffic and air pollution. The city issued a request for ideas on how to implement a congestion-pricing system. Several technology companies sent responses, which a city commission is now reviewing. A pilot could start as soon as 2009 if state legislators approve it.

Last August, the U.S. Department of Transportation awarded a $354.5 million grant to New York for traffic-mitigation research. Miami, Minneapolis, San Francisco and Washington’s King County also received multimillion-dollar grants. Worldwide, London, Singapore and Stockholm all have active congestion-pricing programs. Amsterdam and Seoul are exploring the concept.

While traffic-mitigation projects are gaining steam, other municipal efforts have been floundering—namely, plans to offer ubiquitous wireless Internet access throughout entire cities and towns. Earthlink, once the champion of municipal Wi-Fi network deployments, has dropped many of its plans. Throughout 2005 and 2006, Earthlink won nationwide contracts with a deal in which the company would foot the bill for a citywide Wi-Fi network infrastructure in exchange for the right to sell Wi-Fi services to city residents.

But last July, Earthlink announced that the model wasn’t working: The networks were simply too expensive, and the company needed municipalities to help foot the bill. A month later, Earthlink backed off even further, laying off half its workforce, including the head of the municipal networks division. Earthlink then shelved a municipal Wi-Fi deal with Chicago and pulled out of a partnership with Google to provide Wi-Fi in San Francisco. Since then, prospects for big-city Wi-Fi networks have been dim.

What do gridlock and Wi-Fi have to do with one another?

Plenty, according to entrepreneur Robin Chase, who aims to address traffic congestion and municipal Wi-Fi in one fell swoop. She has a plan for urban vehicle congestion pricing systems that double as enormous wireless hotspots.

Here’s the gist: Drivers who intend to travel into a city’s congestion pricing area will install Wi-Fi “white boxes” in their cars. The devices will communicate with the traffic-congestion system (like an E-ZPass device, but in the 802.11g 2.4 GHz band) and act as wireless access points in an open-source mobile mesh network.

“The intersection is brilliant,” Chase says. And for the past year, she has spent a lot of time talking to technology executives, city officials, academic experts and open-source evangelists about her idea.

Chase is well-respected in the transportation technology industry: She co-founded Zipcar, the world’s largest car-sharing service, which relies on wireless links to record hourly usage and mileage data. She was a Loeb Fellow at Harvard University, where she studied transportation and urban design. And Chase is now CEO of GoLoco, an online ride-sharing community, and Meadow Networks, a transportation consulting firm in Cambridge, Mass.

When Chase talks tech and transportation, people—from urban planners to world leaders—tend to listen.

The Pricing Plan

Mesh networks—including those used in municipal Wi-Fi deployments—dynamically route data packets among wireless access points. Only one access point must be connected directly to the wired network, with several others sharing a connection over the air. In urban Wi-Fi networks, these nodes usually sit on rooftops and lightposts. In Chase’s plan, each car would become a node in a dynamic mesh network, routing and repeating packets of data. The nature of the mesh guarantees there is no single point of failure.

In most congestion pricing plans, including the one New York is proposing, the fee is a set rate determined by time of day and by whether a car enters a certain cordon, or geographic belt, during peak hours. Bloomberg’s leading plan calls for a per-use fee of $8 for cars and $21 for trucks that enter Manhattan below 86th Street between 6 a.m. and 6 p.m. weekdays.

For congestion pricing, a mesh would make it relatively simple for cities to expand—and contract—the pricing cordon gradually, without much additional on-street hardware, Chase says, because drivers would install the wireless boxes in their own cars.

Further, a mesh would enable a system that could measure actual congestion, charging cars according to real-time density rather than arbitrary geography, she adds.

Because her vision relies on open-source technology, Chase was chagrined to see that New York’s “request for expressions of interest” (a precursor to a request for proposal) called for a system that can interoperate with E-ZPass—the proprietary, RFID-based electronic toll-collection system employed on most toll roads in the northeast United States. Thousands of commuters already have E-ZPass transponders in their cars.

She’s hoping that cities considering congestion pricing will also consider driver privacy. As popular as E-ZPass is, it raises the ire of civil libertarians who complain that states don’t always dump individual tolling data from their systems. In fact, E-ZPass records emerged last summer as a popular way to prove infidelity in divorce court: The records could prove that a car and its driver strayed from their usual path, according to Associated Press reports.

To that end, Meadow Networks has developed a “locational privacy” protocol that promises to compute the tolls for a particular driver without being able to reconstruct the driver’s route.

“Most of the existing mechanisms that try to preserve locational privacy do so after the fact,” says Roy Russell, senior consultant at Meadow Networks, former CTO of Zipcar and Chase’s husband. “They rely on discarding information, scrubbing logs, erasing details that are used to create invoice entries, etc. They don’t really preserve locational privacy; they just try to delete the information after it has been collected. They still leave trails, however. Just imagine a bill with each individual line item that shows which toll you went through and how much it cost.

“The Meadow Networks mechanism is quite clever and relies on cryptography and ‘zero-knowledge proofs,’” he says. “It is possible for the tolling authority to know how much you owe while at the same time not know where you traveled and what individual tolls you incurred. So it protects your locational privacy and ensures that you pay the tolls at the same time.”

The Hot Spot Plan

While she can’t predict exact traffic patterns, Chase maintains that in city traffic—even with mitigated congestion—vehicles will stay close enough to each other for an effective wireless signal handoff.

Mobile meshes are nothing new, although historically they have been relegated to public-safety applications. For example, last year Lakewood, N.J., installed a mobile mesh network for its police cars, using hardware from PacketHop, allowing public-safety officials to exchange data feeds while on patrol or en route to emergencies. Several hardware companies, including Motorola, market mesh solutions for vehicles and aircraft.

“Doing a mesh handoff at really high speeds is hard, but in cities, traffic is moving only 7 to 15 miles an hour,” Chase says.

Under Chase’s plan, people who purchase and install the Wi-Fi devices in their cars would receive an incentive—say, the first $100 to $150 in congestion fees free. And if they are built in volume, the in-car devices won’t cost more than $75 each, she says, especially if they are built using standard hardware components and open-source software. The system would include a means of detecting those who neglect to install a box, although this part of the plan is vague.

“I think the best way to do this is carrot and stick,” Russell says. “You have incentives to comply, such as discounted prepaid tolls, coupons that could be redeemed for the installation cost, etc. Then you make the violation penalty really high. You could install automated detection devices, like the cameras that take a photo only when a car runs a light, or you could have [parking enforcement officers] do spot checks with a handheld detector that would alert them when a vehicle doesn’t have a device.”

If commuters complied, the cities would only be responsible for providing key backhaul nodes at places such as critical intersections and exit ramps, Chase says. And unlike in a fixed municipal mesh network, nobody would have to worry about paying a building owner or a utility company for the right to mount the wireless access points on light poles or rooftops, because the access points would be in the cars.

“When we look at the death knells of the [Earthlink] business model, it reiterates why this is brilliant,” Chase says. “It’s end-user installed with an open-source model, so it’s incredibly cheap. Just look at Meraki.”

Meraki Networks is a Mountain View, Calif., startup that picked up in San Francisco where Earthlink left off. Meraki last summer tested a free Wi-Fi network in the city’s densely populated Mission and Castro neighborhoods. The novel part was that rather than dealing with commercial mounting fees, the company asked city residents if they would volunteer to install small Meraki repeaters in their homes. Every box increased the radio signal and strengthened the network.

“It grew really fast,” says Sanjit Biswas, Meraki’s co-founder and CEO. “In less than six months, we had 500 people install the repeaters. They know they’re getting better free Internet access by having it in their window.” In January, boosted by a $20 million round of venture capital, Meraki announced plans to expand the network throughout San Francisco—footing the entire bill for free Wi-Fi and giving residents the option of installing repeaters to increase network bandwidth.

Biswas is quick to say that the company doesn’t plan repeat performances in other cities, explaining that hosting its own boxes for free is not enough of a revenue generator.

“There’s value to us doing this from an R&D perspective,” Biswas says. “That’s our motivation for doing it. But we don’t have plans to run any other networks. Our business is in enabling service providers.”

As for the idea of collaborating on a mobile mesh with Chase, who has shared her plans with Meraki, Biswas says, “We’re starting with baby steps, setting up fixed networks. You have to have all the pieces fit together to be sustainable on any scale.”

Selling a Novel Idea

Chase admits that her concept is a tough sell among government officials and technology companies that would have to be responsible for such a network. There’s good reason for skepticism. Nobody has ever deployed a mobile mesh on such a large scale. The system relies on unlicensed wireless spectrum. And some organizations have not deployed open-source technology.

But she’s selling hard—meeting regularly with city and corporate executives who have shown interest in traffic-congestion pricing. “What’s happened in the past is that I’ll talk to the secretary of transportation or the congressman or the mayor, and they nod, and then they say, ‘Let me get my technology advisers’—typically, career engineers in their mid-50s, who then say it’s wacky,” she says.

But Chase maintains it’s not wacky, it’s just novel.

“Prior to Zipcar, car sharing was considered a fundamentalist, fringe, commercially [unfeasible] venture,” she says. Today, there are tens of thousands of Zipcar vehicles on the road, and 30 percent of the company’s customers have either sold their cars or decided not to buy a car, according to Zipcar’s Web site.

Chase envisions a partnership along the lines of the Apache Software Foundation, an open-source software consortium whose projects include the popular Apache Web server, and whose sponsors include Google, Hewlett-Packard and Yahoo.

“For the open-source mesh network, you’d want to have big companies involved—IBM, Cisco, Google, Intel—three or four of them to back it,” says Chase, who’s in touch with all of them. Cisco’s urban development executives seem impressed with her idea.

“When you look at what happened with municipal Wi-Fi systems—hundreds of them have been created, but most of them have been failing because of the way the business model was designed,” says Nicola Villa, global director of Cisco’s Amsterdam-based Connected Urban Development initiative. Currently partnered with cities such as Amsterdam, San Francisco and Seoul, Cisco aims to decrease vehicle carbon emissions by increasing traffic efficiency through various wireless technologies. Amsterdam and Seoul both have voiced interest in traffic-congestion pricing.

“The cities that have created real impact are those that considered, ‘What am I going to use this for, and how do I create a viable business model?’” Villa says. “We are at a turning point in new business models being created for cities. Those business models are about what kind of [application] clusters will be built on top of the infrastructure. From an application and services perspective, the work that Robin is doing is very much in the right direction.”

The Naysayer Traffic Jam

IBM is the arguable frontrunner in the field of traffic-congestion technology, winning rights to deploy and operate the systems in London and Stockholm. Both cities use an enforcement system in which multiple cameras take pictures of every vehicle’s license plate to record its presence in the congestion zone.

Payment methods vary—drivers can pay via a Web portal, SMS text message, phone kiosks or at convenience stores—but neither city sports an automatic debit system. The cameras record a vehicle’s presence, and pictures of the license plates are sent to a database, which checks the numbers against a list of payers. It’s not a perfect system. The accuracy rate in Stockholm is around 98 percent, according to IBM officials, while accuracy in London hovers around 90 percent.

Hoping to woo IBM with the possibility of better accuracy, Chase and Meadow Networks’ Russell have had several conversations with Landon Miller, a chief engineer at IBM who helps develop Big Blue’s congestion pricing systems. “He did think our approach to privacy was great,” Chase says.

As for the open-source double-duty mesh idea, Miller tells Baseline: “Imaging technology is probably a preferable approach.” He maintains that the validity of the mesh system might be a problem when it comes to legal enforcement.

“In a mesh, the data might skip across 50 cars before reaching the network,” Miller says. “That’s the nature of a mesh. If [a congestion pricing case] goes to court, when you start explaining to a jury that this stuff jumped all over the place, it’s not as convincing as showing them a picture of the offending car.”

Chase and Russell disagree. “The fact that the data is traveling through a mesh network matters little when the data itself is appropriately protected,” Russell says. “Much like an encrypted browser session assures both ends of the connection a high level of security, this would assure the tolling authority that the charge is actually due to the specific transponder.”

“Given the IBM 95 percent reliability, our system would give more compliance,” Chase argues. Says Miller: “We’re working on bettering our license plate technology.”

IBM has submitted its own proposal in response to New York’s request for congestion pricing ideas. In addition to cameras, the proposal addresses New York’s desire for E-ZPass interoperability.

“The E-ZPass Interagency Group [IAG] provides detailed guidelines on how E-ZPass transactions are reconciled among all E-ZPass agencies,” IBM’s proposal reads. “This is primarily done through the exchange of proscribed data files. The format and content of these data files are detailed in a formal, written specification, which is followed by each IAG agency. These data files are exchanged by each agency’s back office by transmitting files to, and retrieving files from, the IAG’s virtual private network. As part of the overall solution, we expect to have software modules specifically focused on handling the reciprocity requirements among E-ZPass agencies.”

Chase maintains that relying on E-ZPass—or any proprietary wireless system—is a mistake. If the transportation industry relies solely on its own wireless protocol in its own band of the spectrum, that cuts the industry off from possible interoperability efforts, such as hers. The transportation industry’s Dedicated Short Range Communications protocol offers communication between vehicles and roadside equipment. It runs in the 5.9 GHz band in the United States. Wi-Fi runs in the 2.4 MHz or 5.8 MHz range.

“Every other sector in the economy is finding secure, reliable and economical systems that use Internet Protocol and are highly compatible,” Chase writes in her blog, Network Musings. “Continued insistence on separate radio frequencies, closed networks and obscure proprietary standards mean that technology investments in transportation don’t take advantage of low-cost, high-volume components developed for the consumer market or advances in communications hardware and routing software.”

And regarding transportation and the Internet, while Cisco has yet to fund her idea, Chase and Cisco seem to be remarkably like-minded. At a recent Cisco Urban Development event in San Francisco, Cisco introduced a “connected and green bus,” which aims to save energy and improve traffic flow by streamlining the transit system’s communications technology.

“What happens in every major city’s [public transportation system] is that every time you add a new function to the bus, you have to add new infrastructure,” Villa says. “You have one infrastructure for video streaming, one for location, one for voice communications, one to stream the telemetrics of the bus, one for payments. We’re integrating those technologies into one by placing an IP-based mobile access router [on the bus] so all the communication goes over IP.

“We consider the bus like a node in the network, so you’re moving toward a mobile infrastructure,” Villa adds, noting the similarity to Chase’s idea.

And Cisco is paying close attention to Chase’s efforts. “I see Robin as one of the global thought leaders of transportation technology,” Villa says.

Allies in the open-source community are hopeful.

“It’s completely doable with the technology that’s available today,” says Sascha Meinrath, research director for the Wireless Future Program at The New America Foundation, a Washington public policy institute and think tank, a leading expert on community wireless networks and a member of the Meadow Networks board.

“There’s pretty much no scalability limit and no throughput limit. We’re 80, 90 percent of the way there. It’s just a matter of finding a municipality, a company, a patron willing to fund this.”