ON A CHILL MORNING in late January of 2007, Paul Minett, a mustachioed man with a clean pate, a notebook, and a pleasant if un-pin-pointable accent, spent the better part of two hours standing near a Safeway grocery store at the intersection of College and Claremont streets in Oakland, California, where, from an unobtrusive distance, he observed a group of people on a sidewalk. He took careful notes and tabulated their movements, as if studying the behavior of a rare animal in the wild. The target of his observation was a group of commuters leaving downtown Oakland for downtown San Francisco, and doing so by means of an informal carpooling program that emerged after the 1973 Arab Oil Embargo and has continued ever since. Having no apparent leadership or hierarchy, no president, no boss, no board of directors, no office of any kind, it’s as close to a pure, functioning, community-based system of transit infrastructure as one can find these days, and one by which, for more than forty years, from fixed locations across the Bay Area, some six thousand people have commuted into downtown San Francisco every day.

It is breathtakingly low-tech and effective, a grassroots, improvisational solution to traffic congestion (similar ad-hoc carpooling programs exist in Houston, Texas, and in Washington DC, where the practice is thought to have originated). You show up, a stranger pulls up in a car, you get in, and (while the idled, sputtering masses stew in traffic) you arrive at Fremont Street, downtown, all for about a dollar donation to the driver.

For the commute back, you go to Beale Street, a block away, and line up at one of the dozen or so signs that list destination points—Vallejo, Richmond, El Cerrito, Fairfield, or the North Berkeley BART (Bay Area Rapid Transit) station. Drivers benefit from access to high-occupancy vehicle (HOV) lanes, which can cut the commute by an hour or more both ways, and, unlike other carpooling arrangements, the system has the further advantage of requiring no ongoing commitment or obligation to return home with the same driver. In Washington DC and in Houston, it’s known as “slugging,” but in California someone long ago recognized something sexier in this swinging, guilt-free form of commuting, and the name casual carpooling stuck.

“Cars arrived and waited for riders,” Minett wrote of the Oakland commuters he observed. “Riders came and got into their cars, usually two per car on a first-come first-served basis. I saw partners arrive with partners, kiss, and part. Some waited to make sure that their partners got off safely; others left without a backward glance.” He noted that more than half of the people commuting that morning were female. Two women were walking their dogs. “One got a ride, the other carried on with the dogs.” The scene he was describing, in other words, was completely quotidian: “I saw an original VW Beetle, and a lady who got into it with a huge suitcase, and they still took a second passenger.” Later on, in a coffee shop, Minett was able to conjure his quarry in greater relief. “I’d witnessed,” he says in a YouTube video about that moment, “a community of unconnected people who share a solution to their real need and are not afraid to share their trip with a different driver or rider each day.” It was, he says memorably, “a silent transit system that is based on trust.”

Inspired by the Bay Area’s casual carpooling phenomenon, Minett devised his own idea, “fixed route, flexible car-pooling,” in which commuters drive from their homes to a nearby spot, a “Park and Ride” lot, for example. If you want to be a driver that day, you pick up passengers; if you want to be a passenger, you leave your car at the Park and Ride and join a “slug line,” where other passengers are waiting. Minett’s model adds technology to the mix—using web-based tools to establish membership, to exchange incentive points, to pre-screen drivers, and the like—but it operates chiefly around the idea of meeting places where people can go to find a ride to work. This phenomenon is now commonly known as ridesharing and, according to Minett, it’s 80 percent cheaper than riding the bus.

The search for the new commute, in which an assortment of agencies and private companies are looking for more efficient ways of getting people from A to B, is taking place against a backdrop of disquieting trends. The transportation sector now accounts for more than 19 percent of global energy consumption and between 15 and 22 percent of global CO2 emissions. Cars and other light-duty vehicles make up most (52 percent) of that global energy use and, with petroleum products the overwhelming fuel source, most of the CO2 emissions. Cars aren’t going away, either. The sheer number of cars worldwide topped 1 billion in 2010, and projections suggest that figure will increase to 1.6 billion by 2025. By that time, there will be 1 billion more people on the planet, with half of the world’s population having entered the middle class. The World Economic Forum estimates that a staggering $4 trillion will be required annually from now until 2025 just to meet the global demand for infrastructure, much of it transportation related. Add to that an anemic public sector hamstrung by austerity measures, and factor in the phenomenon of “latent demand” (the more roads you build, the more people decide to use them), and soon a bracing, yawning chasm seems to emerge—with no likely way to satisfy it with the physical systems we’ve devised since the Roman Empire to get people around. There will simply be too many people, too many cars on the road, and the lag time in infrastructure construction to address the oncoming traffic problems will be too great to prevent a global bottleneck. In short, we won’t likely build our way out of this problem.

Americans already spend an estimated 463 hours, or 19 days annually, inside their cars, 38 hours of which, on average (almost an entire work week), are spent either stalled or creeping along in traffic. Because congestion is now so prevalent, Americans factor up to 60 minutes of travel time for important trips (like to the airport) that might normally take only 20 minutes. All of this congestion is caused, to a significant degree, by a singular fact—that most commuters in the U.S. (76.4 percent) not only drive to work, but they drive to work alone. For people like Paul Minett, this number represents a spectacular inefficiency, all those empty and available passenger seats flying by on the highway like a vast river of opportunity. And so the next realm of transportation solutions is based on the idea that if we can’t build our way out of our traffic problems, we might be able to think our way out, devising technological solutions that try to fill those empty seats. A lot of that thinking, it turns out, has been happening in San Francisco.

ON A SUNNY DAY last June, I joined three young women on their morning commute from San Francisco to a business park and BART transit hub near Walnut Creek, California. The trip was organized as part of WeGo, a ridesharing pilot project that was being tested in Marin, Sonoma, and Contra Costa counties. The goal of the project, a partnership between an Irish software-development company called Avego and the Metropolitan Transportation Commission (MTC), was to take carpooling to the next level by adding the dimension of real-time ride procurement to the morning commute. Some called it “dynamic” ridesharing, and a recent study defines it as “a single, or reoccurring rideshare trip with no fixed schedule, organized on a one-time basis, with matching of participants occurring as little as a few minutes before departure or as far in advance as the evening before.” An architecture of new technologies surrounds the real-time ridesharing concept and includes network connectivity, GPS functionality, a software algorithm that matches people up, and one all-important element: a database of names and information about potential riders. Think of it as a social network that connects riders with drivers—another instance of the general economic shift from things (cars, in this case) to services (a mobile app that helps you find a ride). It’s a transportation solution that points toward a world with fewer cars on the road (and less congestion), one in which you could step off your front porch, find a ride to work or to the grocery store with someone who was also headed that way, all in the spur of the moment by simply using your mobile phone.

First launched in 2008, Avego’s ridesharing commuter app promised to extend the social media cloud in ways that could land you happily in someone’s unused passenger seat. Sean O’Sullivan, the company’s founder, has described their product as a cross between car-pooling, public transport, and eBay. By using the app, one could, within minutes, or perhaps a day in advance, find a ride with someone going from downtown San Francisco, say, to Sonoma County—with no more planning than it takes to update your Facebook page. Put this tool in the hands of many tens of thousands of users, so goes the vision, and add to it a platform for evaluating riders, a method of automated financial transactions, and a variety of incentives and rewards for participating in the scheme, and you could have something truly revolutionary on your hands.

Urban planners like Mark Hallenbeck, director of the Washington State Transportation Center at the University of Washington, see ridesharing as evidence of a paradigm shift from “thinking about corridors”—about building more and wider highways, for instance—to “thinking about markets.” That shift is happening in large part because there’s nowhere to put larger roads. Seattle, for instance, sits between two topographically limiting features—Lake Washington to the east and Puget Sound to the west. Interstate 5, the main north-south corridor on the West Coast, runs between the two. Widening Interstate 5 to eliminate traffic delays would require the construction of an additional fourteen lanes, according to Hallenbeck. “The reality is, that’s not going to happen,” he says, and not just in Seattle, but in most urban centers. “So, you say, what’s next?” Ridesharing could be one answer, harnessing the vast reservoir of empty seats and, in market terms, giving those empty seats a value, creating liquidity in a new marketplace of seats, passengers, and drivers.

IT’S WORTH PAUSING HERE to make a distinction between ridesharing and so-called peer-to-peer taxi services like Lyft, Uber, and Sidecar, which have gained considerable traction in larger cities. This became clear to me when, on my first day in San Francisco, I used Uber to arrange a trip from Japantown to Fort Mason in the Marina District. In the lobby of my hotel, I opened my Uber app and got a message that said, “Jose will be arriving in three minutes.” I walked out of the lobby, past the taxi stand, and within seconds a car slid up beside me, tinted window rolling down to reveal a handsome, friendly face asking, “Mark?” Jose was no shlub. He drove his own car, which fairly sparkled inside and out. He offered me a bottle of chilled water. Another driver, a beautician who asked to be called Amy because her boyfriend didn’t know she was working for Lyft, distributes late-night hangover gift bags. She arrived to take me to an interview waiving a Lyft trademark pink mustache out of her sunroof, and soon commenced a GPS-assisted navigation across town that seemed part taxi ride, part amusement park ride, and part therapy session. At the end of the trip, I wanted to pay my fare and ask her to marry me. Of course Lyft/Uber/Sidecar weren’t actual bona fide “ridesharing” operations, as Brant Arthur, manager of the WeGo project in Sonoma County, reminded me. “They weren’t taking cars off the road—they were just people driving around town in their own cars making extra money.” They were basically, in his words, “unregulated taxis.”

But an entrepreneur named Paul Kogan saw something striking in the way the Lyft app allowed you to view all the potential Lyft drivers in your area, in real time. With the help of a few partners, he founded a company called Hovee, and in May of 2013 launched a series of beta tests at several large Bay Area tech firms. “Our trigger was that screen,” Kogan told me. “The fact that you could now do this was important.” By “this,” Kogan meant match people up to share a certain experience. Kogan’s team turned to dating services for inspiration. They looked at the mobile app Tinder, which helps people locate each other for encounters of the flesh. “What’s interesting about carpooling services,” says Kogan, “is that you always come back to the dating analogy.” It was, of course, the analogy that Kogan’s team was interested in—transportation match-making to facilitate shared rides.

The big challenge for any database-driven ridesharing scheme, according to Kogan, is getting enough people into a database in order to create reliable matches. “It’s a classic chicken and egg problem,” Kogan says. “You need a good application, but without enough users, your application won’t give riders the matches they want.” Hovee began by targeting a limited demographic segment—knowledge workers at the big tech corporations in the Bay Area. “Let’s say he or she is someone who works at one of the big tech companies on the peninsula,” says Kogan. “Every day that person drives from Noe Valley to Facebook, for example, on the 101. What we realized is that forty minutes alone by him or herself, from a corporate perspective, is a terribly unproductive way to spend that time.” This is where Hovee’s match-making kicks in, helping people from similar lines of work find each other, so that the physical hook-up is replaced by networking and shop talk on a shared commute. “They can schmooze if they want or talk about surfing. The social connection is what’s going to tip the base for us,” says Kogan.

Hovee’s platform adds several elements of accountability to the mix: members must work at an established company; everyone signs in using work e-mail; and everyone must include a LinkedIn profile, so that the element of “stranger danger” is eliminated. “If people can know who they’re riding with,” says Kogan, “if they can see the full name, the company, their title and job function, if it’s someone from another division of a company, or someone from the same industry, and if you can have precise control over who gets in your car, that will make the shared ride something to look forward to instead of a chore.” By targeting the tech giants, moreover, Hovee hopes to hop right over the chicken and egg problem. “Part of what we’re doing is about efficiency and part of it is social,” says Kogan. “People want to connect. It’s not just utilitarian. It’s human nature.”

AVEGO HAD FOLLOWED a different path to building ridership. At the Walnut Creek BART transit hub, I watched as auburn-haired, laser-eyed Teresa Gaynor, project manager for WeGo Marin, installed herself behind a folding table under a tent alongside other tables and tents at a business park’s version of a farmer’s market—block after block of concrete and tinted office windows, a patch of grass, a vegetable or two on display, somebody beginning to play an acoustic guitar over an amplifier. Teresa offered a smile to the occasional passerby, inviting them to sign up for the company’s ridesharing program. The approach made sense—sign up potential riders where they work, build a partnership with all of the employers in the area. And indeed, people came to Teresa’s table and signed up. But I couldn’t help thinking, also, that no matter how many tables WeGo set up in business parks across Sonoma, Marin, and Contra Costa counties, the effectiveness of this strategy seemed a bit beyond the scale of the task. It was like trying to build an alternative mass transit system by having a bake sale. In eighteen months, fewer than two thousand people had signed up across all three counties. “It wasn’t scaling,” said Paul Steinberg, vice president and director of business development for Avego.

Then, on July 1, 2013, a massive Bay Area transit strike brought the term “carmageddon” back into the lexicon. The event, in which two thousand BART employees brought a system that normally handles 400,000 commuters a day to a standstill for an entire week, created an opportunity for Avego to shift recruitment tactics. According to Steinberg, the MTC called to ask if Avego was prepared to handle some of the commuter overflow. Steinberg said it could, and the company was given the green light to ramp up its efforts to attract new riders. They began circulating thousands of imitation BART tickets that advertised their system; got their own buses and vans and offered one-time free rides; raffled the chance to win helicopter commutes to work; and created a new website, bartstrike.com, which recommended alternative ways for Bay Area citizens to get to work. In a kind of public service announcement video on the website, Sean O’Sullivan even touted the advantages of casual carpooling, explaining to viewers how the system worked and how to find a ride. At the same time, the company launched its own version of casual carpooling, with a system of hubs where people could queue up and find rides, using the company’s app as a method of offering a donation to each driver.

As a result of the strike and the company’s associated marketing efforts, Avego’s database jumped from under two thousand to about twenty thousand subscribers. “We solved the chicken and egg database problem in about three to four days,” says Steinberg. Some of those riders disappeared after the strike was over, but what remained were hundreds of commuters who might now begin to consider ridesharing over other options. One month later, the company changed its name from Avego to Carma. “Carma is a summary of what you’re doing when you’re using our product,” says Steinberg. “You’re not going to make a lot of money, but you’re doing the right thing. Share a ride with someone today, and then later, when you need it, someone will share a ride back.”

In October 2013, Carma was granted lead vendor status in the Bay Area, which gave the company strategic control of all the area’s ridesharing pilot projects, and with that, Carma has continued to tack hard toward the “meeting places” model. Carma is now engaged in deploying a set of Carma Hubs across from BART park and rides and has extended the casual carpooling idea into untested areas—one corridor along Highway 680, from an area called Bishop Ranch to Walnut Creek, and another corridor on Highway 101 between Marin and Sonoma counties. The company recently received permission to use the bus stops along these two corridors as Carma-branded, casual carpooling meeting places. “So if you’re a driver and you see people waiting for a bus, you can now legally pull over to the bus stop and pick up riders.” These hubs will also channel riders into Carma’s system. Nearly 60 percent of people who have used a Carma hub at least twice have begun to use the company’s app and database, according to Steinberg.

But the biggest evolution of the ridesharing idea is a project that Carma is beta testing in Austin, Texas. “What we want to prove,” says Steinberg, “is that it’s easier and more effective to find rideshare participants at the point of origin—at people’s homes—than it is to build a ridership from the destination point—the employer.” The typical approach so far has put all the focus on the commuter’s destination. “But that gives you a hub and spoke problem,” says Steinberg—it becomes difficult, with all those commuting routes coming in from different destinations, for people to find ridesharing matches. So Carma decided to focus on the point of origin—on a single neighborhood, or a group of neighborhoods near each other, and doing so made the commuting picture look quite different. “It looks like a fork,” says Steinberg, with, say, four different but somewhat parallel routes tapering into a single major highway corridor, ending at the employer. Carma tested its rider application in six different neighborhoods in the Austin suburb of Leander. According to Steinberg, about a third of the Leander test community now uses the Carma app at least once a week. As an added incentive, when commuters share a ride using the Carma app, the Texas Department of Transportation offers toll credits to the drivers. Carma has since begun reaching out to potential riders by going through neighborhood associations, a strategy to test whether organizing at the neighborhood level will be the key to building ridership.

THE ULTIMATE SUCCESS of ridesharing, of filling all those empty seats on the highway, may hinge on finding ways, in effect, to unseat certain locked-in views of travel, according to Mark Hallenbeck. In his Seattle office, not far from the oceanic roar of Interstate 5, the slender, wire-rimmed, buttoned-down urban planner invoked a concept of travel that seems close to an American birthright—that the American road should be, in effect, free for all. But that view, he suggested, creates problems analogous to the old Soviet bread lines. When bread was dirt cheap, everyone grabbed an extra loaf or two. Bakers had no incentive to make more than their quota. “So, if you wanted bread, you had to get up early and wait in line.” Traffic congestion is like Soviet bread lines, and so, in order to alleviate the resulting congestion, some cities have instituted what’s known as value pricing—charging higher tolls for travel during peak time periods. When it comes to road use, nothing is ever free, according to Hallenback. “You pay with money, or, in a traffic jam you pay with time—either way, you pay.”

Paul Minett, however, believes that the real emphasis should be on putting a value on “passengership.” Minett likes to point out that a big difference could be made without any technological advances or complicated algorithms. If all current drivers left their cars at home and became passengers one day per week, there would be 20 percent reduction in traffic volumes and a likely reduction of the worst kinds of congestion. With some technological and policy adaptation—using radio frequency identification (RFID) tags and big data analytics to track levels of traffic, using mobile applications like Carma or Hovee, and putting a value on passengership, even more could be done. “Value pricing shouldn’t be about raising tolls—about tolling people off the roads. It should be about making the system visible, so that communities of drivers can switch to become passengers when it’s needed,” says Minett. He would also like to see a fair market value put upon parking at the destination end of the commute, so that when drivers opt to become passengers, they receive cash or credit for the value of the parking spot they do not use on that day. “People who are prepared to switch are the most valuable people in the system,” says Minett, “and they should be treated very well, because if they switch, it makes the traffic better for all.” If we can effectively incentivize passengership, according to Minett, then we can deploy the power of communities to become active agents in their own traffic destiny.

Communities, by now it almost goes without saying, have proven to be resilient and resourceful agents of change in human affairs, and signs seem to indicate that they may be an important part of the solution for the American commute, the getting from home to work and back. The environmental and economic consequences of the single-rider form of “modal choice” are well known. Traffic congestion in the United States alone adds 56 billion pounds of CO2 emissions to the atmosphere, wastes 2.9 billion gallons of fuel annually, and costs drivers $121 billion per year. It’s a very big problem that preoccupies multiple agencies at the United States Department of Transportation (DOT). And though that sprawling bureaucracy is responsible for, among other things, improving the safety and efficiency of air traffic, maritime shipping, pipelines, railroads, trucking, and even the continued management of the St. Lawrence Seaway, the DOT has also begun to focus, at least in principle, on leveraging the power of communities. Its “Livable Communities” initiative, “a transformational policy shift,” according to the DOT’s 2013 budget report, represents a new effort, at the largest level of governance, to bring federal funds to bear upon traffic congestion at the community level. And that, like Minett’s idea of giving people an active role in solving their own transport problems, goes to the heart of what it means to commute—a word whose etymological origins, after all, embrace both community and change.

See an audio slide show about ridesharing here, and learn more about Orion‘s Reimagining Infrastructure series here.