By on September 30, 2021

As luck would have it, hiring thousands of drivers to cruise around a city in search of their next fare has some negative environmental impacts. That’s the word coming from expert researchers at Carnegie Mellon University, who we can only hope are prepared to tackle similarly impossible quandaries — like establishing what happens to an object when it’s dropped or reaching a final determination on the wetness of water.

The study is inextricably linked to one we covered in 2018 asserting that ride-hailing services actually created more traffic congestion because it treads extremely familiar ground and seems like something that we should have already figured out on our own. But it’s also at odds with the years of messaging we’ve gotten from technology firms that have promised on-demand services (like Uber or Lyft) would usher in a new era of urban transportation striving for clearer roads and cleaner air. Based on little more than the conjecture of executives, we’ve generally accepted ride-hailing as “greener” than the alternatives and it’s well past time that we started actually thinking about it. 

Shared by Automotive News, the Carnegie Mellon study suggests that ride-hailing applications add to air pollution for most of the same reasons earlier probes used to determine they also exacerbated traffic congestion. Their convenience often makes them a desirable alternative to public transportation, drawing riders away from subway and bus lines. But they’re not convincing riders to abandon vehicle ownership and frequently require drivers to putter around the city aimlessly as they wait for their next customer.

The above has certainly been true for your truly. Despite living extremely close to most forms of public transportation, the Manhattan Transit Authority (MTA) has become so unreliable that I really only use it when time isn’t an important factor or I want to save some money. Uber often gets my business whenever the weather is inclement or the local parking situation is going to bankrupt me while requiring I leave half an hour early. But the rest of the time I am probably going to opt to drive myself — especially if I’m venturing beyond the confines of New York City.

From AN:

There is some promising news. Researchers at Carnegie Mellon University simulated replacing private vehicle travel with ride-hailing services across six U.S. cities. Because vehicles emit more pollution during “cold starts” and because ride-hailing vehicles tend to be newer, this swapping, as simulated, could spur a 50 to 60 percent decline in emissions.

But there’s a practical downside: Ride-hailing vehicles create about a 20 percent increase in fuel consumption and greenhouse gas emissions because of “deadheading,” the miles driven without paying customers.

That augments findings from MIT and Harvard researchers, who wrote this month that even fleets of all-electric robotaxis would not reduce pollution and, in some cases, may actually create more pollution.

Beyond emissions, the Carnegie Mellon researchers say overall costs associated with traffic congestion, crashes and noise increase by 60 percent with ride-hailing vehicles. These “externality costs” are tripled when ride-hailing replaces public transportation.

The Harvard study recommends continued remote work, increased ride pooling, staggered employee schedules, and ensuring leisure activities occur during off-peak periods. But it still determined that there are a lot of reasons to assume widespread adoption of self-driving taxis could have a negative environmental impact, especially in places where vehicle ownership is a necessity (rural areas) or the market is already oversaturated with traditional taxi services (big cities). Unfortunately, it hinted that central planning and shrewd policy decisions could be the way to mitigate those problems — positing a solution without actually having to give relevant details.

“Limitations notwithstanding, the robustness of our effects leads us to several conclusions,” reads the report’s final paragraph. “First, [autonomous taxis/ATs] can financially compete with [conventional taxis/CTs]. Our model estimates that CT-to-AT substitution represents a viable pathway towards addressing technical inefficiencies and public health concerns surrounding gasoline use. Second, we document that the inability of ATs to achieve cost parity with [personal vehicles] may not preclude the realization of negative energy externalities. Third, we show that the magnitude of these outcomes depends on key interactions and dependencies between supply-demand matching inefficiencies and homogeneity in trip timing behavior. Finally, we document specific pathways and the requisite thresholds required to reduce energy consumption and emissions. Leveraging these pathways is — we believe — key to fostering greater environmental stewardship absent impediments in economic mobility.”

But the more pertinent concern should be that ride-hailing services are discouraging people from using mass transit and there was a joint paper, published this week by researchers from the University of North Carolina and the University of Michigan, tackling exactly that. Entitled Transit’s downward spiral: Assessing the social-justice implications of ride-hailing platforms and COVID-19 for public transportation in the USthe paper suggests that the Uber’s of the world are effectively creating a situation where declining ridership has made it impossible for cities to maintain subway systems and bus fleets. While I would argue that city mismanagement has also played a factor — as my subway stop has been remodeled to look lovely but the trains are never on time — the general argument remains valid whether or not you bother to entertain the social justice or pandemic-related aspects included in the article.

This one is tough for me because all the above research papers have correctly identified that ride-hailing (autonomous or otherwise) is bound to exacerbate pollution and traffic congestion. But the proposed solutions are frequently overbearing and sometimes encourage laws that would limit when and how people drive. We should also be curious as to the tangible environmental harm associated with these issues. While a 20-percent increase in vehicle emissions stemming from ride-hailing certainly sounds unsavory, how does it impact our planet vs something like using massive tanker ships to import oil into the country? Would transitioning toward nuclear power and/or renewable energy sources be able to offset these problems? And what about the economic fallout from micromanaging traffic vs taking a totally hands-off approach?

While those questions are explored in some of the aforementioned research articles, none of them stick their neck out to make definitive assertions. But those still seem like the questions we should probably be answering. Because it should have already been obvious to people that ride-hailing companies were clogging up metropolitan roads and emitting greenhouse gasses. We need to decide if what is worth tolerating and establish the ramifications of taking one course of action over another. Otherwise, we’re bound to make stupid decisions subsequent generations will have to contend with and may ultimately despise us for.

[Image: Jonathan Weiss/Shutterstock]

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41 Comments on “Captain Obvious Returns: Studies Say Ride-Hailing Apps Cause Pollution...”


  • avatar
    Lou_BC

    “Ride Hailing” is just a gig economy shift in who is responsible for the vehicle. If one owns a taxi company, that owner is responsible for purchase, insurance, maintenance, repairs and paying the driver’s wages etc. If you own a “ride hail” business then the driver is on the hook for most of the costs. Fuel consumption and emissions isn’t going to change whether it’s a taxi or “ride-hail”.

    • 0 avatar
      indi500fan

      I’ve always felt that Uber/Lyft were a money loser for the driver/owner if full costs are taken into account. Especially with $4 gas, spiking tire prices, etc. Now they have been around quite a while which makes me wonder if they’re just recruiting new people, or have some folks actually made this a true money maker?

      • 0 avatar

        @indi500fan If you think so then nobody prevents you from paying generous tips to Uber drivers. And also paying MSRP for a new car because it would be only fair to car dealers and their employees who have families and want to have nice vacations and buy nice things.

      • 0 avatar
        stuki

        “if they’re just recruiting new people, or have some folks actually made this a true money maker?”

        It doesn’t really matter, does it? A big reason for the efficiency of free markets, is specifically because some/many are willing to pay for the privilege of rolling the dice, despite being faced with Casino odds.

        At the same time, a big reason our no longer free markets are, as expected, no longer working; is specifically that those who have the ears of politicians, want to bar others willing to do just that, from competing with them.

        The “classical” axiom that (monetary) risk is always, to everyone, a negative by deductive fiat, simply does not pass muster neither theoretically nor empirically.

        • 0 avatar
          conundrum

          What a load of rubbish. The spouting of free market dogma is the sign of the uncritically brainwashed, a Pavlovian response based on people agreeing with themselves.

          What a hoot. But typical of the neoliberal mindset.

    • 0 avatar
      stuki

      Because of idiotically sclerotic “employment laws,” cab companies cannot be as flexible as owner-operator contractors bringing their own vehicle. Flexibility is a valuable good. When you need a ride, standing around tapping your feet is a very poor substitute. Doubly so if you also have to pay extra for all the hours your driver spent blowing smoke at a cabstand.

      Cab demand is very intermittent. It makes no sense at all, to regulate staffing and available cars up front, instead of letting demand drive supply real time. When lots of people need a ride, prices are bid up (although current ride-share cos are still a bit stiffer than ideal), so that guys who otherwise would study for midterms (or smoke weed), jump in their cars and help alleviate bottlenecks.

  • avatar
    ToolGuy

    On zillow.com, my neighborhood (4 miles from city center, population over 100K) has a Walk Score® of 2. On a 100 point scale, I’m a 2. This is deep in “Car-Dependent” territory:

    https://www.walkscore.com/methodology.shtml

    I often go for walks with my spouse. The Greenway where we sometimes walk is awesome (we might do 3-4 miles). We take a short drive to get there (there are no sidewalks between here and there, but there are many Opportunities To Die In Traffic).

    The Greenway is currently about 12 miles long and I sometimes ride my bike there (taking my life in my hands for the first couple miles which include a narrow bridge shared with vehicles going ~50 mph).

    TL;DR: I can walk to walk. I can bike to bike. There is no good, easy or safe way to walk or bike to anywhere ‘useful’ (ex. running errands). This is very typical for a lot of places in 2021 – and in my opinion, Kind of Stupid™.

    • 0 avatar
      NigelShiftright

      And America is full of millions of ToolGuys. People who were forced at gunpoint to live in neighborhoods and take jobs in places where they could not walk everywhere they needed to go.

      Won’t you help? Please make a generous contribution to New Lifestyles For The Car Dependent today!

      • 0 avatar
        SoCalMikester

        bought a condo in so cal 8 miles from work and most of the time its a straight shot up the 605, in the carpool lane doin 80. 10 mins, max. car is driven maybe 6000 miles a year. an EV wouldnt be worth my while, even if gas was $10/gal.

        and even then, the garages are all across the way, 80s vintage, with a single 120v for lights and door openers. rewiring them all would be a pretty big undertaking

        • 0 avatar
          el scotto

          @SoCalMikester Sir, it wouldn’t be a rewiring, it would be adding another electrical line. Same deal as putting in wiring for an electric dryer. You might need a new breaker box for the new breaker. 4-6 hours job, all day if they’re milking (HOA is paying) it. 80s vintage means they should still be up to codes. If you need rewiring to put in a car charger, your whole condo will need rewired.

      • 0 avatar
        ToolGuy

        @NigelShiftright,

        Beginning anywhere in the U.S.A., borrow someone’s 12-year-old kid. At 1pm, drive to the nearest Target store and drop the kid off. Have them walk to the nearest Chick-fil-A (if less than ~1.5 miles) and go inside. Repeat this experiment over at least 3 consecutive days using different kids and starting at different Target stores.

        Then ask the kids what they think of the current state of urban planning in America. Ask their parents what they think of your experiment.

        (You might want to have an EMS team on standby.)

        • 0 avatar
          NigelShiftright

          Back at ya @ToolGuy, and thanks for replying.

          You could not possibly operate a Target store based on the number of customers who live within walking distance. Suppose you tore out five city blocks of northside Chicago or of Queens and planted a Target, with no parking, in that space. Do you think it would work?

          Chick-fil-A might. There are many fast food joints within walking distance of urban neighborhoods all over the country.

          I’m probably older than you. I grew up in a Chicago neighborhood where my dad had a car and my mom didn’t learn to drive until I was about 15. Dad worked from 7 to 5, five days a week.

          So grocery shopping was a mile walk to a typical city “supermarket” (maybe 3000 square feet) once or twice a week, with me pulling my Flexible Flyer home full of her purchases. In Chicago winters, too. Dad couldn’t drive there evenings or weekends – almost no parking.

          When she had to take me or my kid brother to the doctor or dentist, it was two buses with a transfer, each way. Say 1.5 hours roundtrip, plus the time in the office. More if any bus was late.

          And we walked or biked 3/4 mile each way to school, in all weathers. Starting in first grade. (This was before the news media had American parents convinced that there were a dozen pedos lurking on every block).

          Let’s see how many American families want to bring back -that- lifestyle!

  • avatar
    Master Baiter

    Leftist totalitarian playbook:

    1. Find something you don’t like. Let’s call it X. In this case, X is ride sharing services.
    2. Fund a bunch of scientists to write studies showing X causes pollution, causes climate change, or hurts persons of color. Better yet, establish that all three are true. If you can include the words “Social Justice” in the name of your study, you are golden.
    3. Get your cronies in the media to publish the results as headline news, knowing the ignorant populace won’t read the fine print.
    4. Accuse any skeptics of being science deniers.
    5. Cram laws prohibiting X down the throats of the populace.

    Rinse and repeat.

    • 0 avatar
      Lou_BC

      Mr. Posky did a good job of outlining the obvious which was studied i.e. “ride-hailing” adds to traffic congestion and pollution as opposed to this service being sold as “greener”.

      This has zero to do with your rant.

      • 0 avatar
        Master Baiter

        “This has zero to do with your rant.”

        Typical reflexive disagreement from Lou the black Labrador.

        The study is promoting public transportation–something the totalitarian Left has been pushing forever. Public transit is for the poor, and the Left would love nothing more than to make all of us live like the poor.

    • 0 avatar
      RHD

      MB – other than out of your own orifice, what source do you have for this “playbook”?
      You wouldn’t know a liberal if you saw one, much less truly understand what they think. A “totalitarian liberal” to you is what you imagine it is, some sort of amorphous enemy, and your concept has very little to do with the real world. Your fears are unfounded, and are self-created.

      • 0 avatar
        Master Baiter

        “Your fears are unfounded.”

        I wouldn’t call it fear so much as white hot hatred.

        And I have no problem with classical liberals–I would consider myself one. I’m talking about the new breed of woke SJWs who are in fact totalitarians, and they are not figments of my imagination.

        • 0 avatar
          Lou_BC

          @Master Baiter – your whole “scientists are paid to generate results in keeping with their master’s wishes” theory is rather easy to refute.
          I read somewhere that the USA spends roughly 26 billion researching and mitigating climate change. I’ve also read that oil companies generated 180 billion in profits. It would not be too hard for oil companies to outspend climate change research/mitigation.

    • 0 avatar
      wolfwagen

      Transit’s downward spiral: Assessing the social-justice implications of ride-hailing platforms and COVID-19 for public transportation in the US = UBER, LYFT, etc. are racist and must be destroyed. GOOD GOD WE ARE SCREWED!!!

    • 0 avatar
      28-Cars-Later

      “scientists”

    • 0 avatar
      SoCalMikester

      sounds just like the GOP, but controlling what women do with their body

  • avatar
    fazalmajid

    Are they really cruising, though? I can’t imaging they enjoy wasting gasoline without a ride.

    I’ve seen estimates that 30% of urban traffic at peak times is people looking for parking, and Ubers save you that.

  • avatar
    DC Bruce

    There are very few US cities where mass transit really might substitute for individual vehicles. The one that I can think of is New York. Theoretically, the density there should make it economically viable to have sufficient transit frequency of service to make it more convenient than a private car, whether for hire or individually owned. Sadly, it appears that New York’s transit system is failing. Seven or eight years ago, I could get up, get dressed and leave my house in Washington, DC, ride the subway to Union Station, board the Acela train for New York, ride the NY subway and be in court inn Brooklyn at 9:30 a.m.

    This seems like a minor miracle, in retrospect.

    I’ve never been impressed with Uber and Lyft as replacement for taxi service. Initially, they offered two things: prepayment with a credit card and vehicles that were in better condition than the typical DC cab. These issues were eminently fixxable without all of the techie hype. And, in the old days, most cabbies knew where things were and how to get there. At least once, I bolted from an Uber car whose driver was trying to navigate Manhattan with a GPS . . . to find the federal courthouse.

    As for the study . . . well, the most you can say is that it’s work like this that keeps its authors out of trouble on the streets.

    • 0 avatar
      el scotto

      @DC Bruce. I live and work in DC and am in total agreement with you. NYC and DC may be the two big cities in the U.S. where public transportation is quicker and a great deal cheaper. I don’t think that some of our readers understand they will see people in business attire on the subways and buses of NYC and DC. The alternative is to fight horrid traffic and pay a king’s ransom to park for the day. If you can find a place to park. Uber Black seems to work for me when I have to take a rideshare. I do wish some of the public transportation naysayers could observe the Pentagon Transit Center. No one will ever write a ballad extolling its virtues but it does what it was designed to do. Get people on their way.

  • avatar

    Why do they need to cruise if rides come over the phone and include customers address. Doesn’t it make more sense just to park somewhere and wait?

  • avatar
    Master Baiter

    “Doesn’t it make more sense just to park somewhere and wait?”

    That’s most likely exactly what they do, but the authors of this bogus study started with the conclusion and then made up “facts” to support it.

    • 0 avatar
      Matt Posky

      In NYC cabs and black cars often do park and wait in designated areas where passengers are likely to arrive (airports, the biggest subway stations, major event spaces) but Uber/Lyft drivers cannot use these areas to park and often have to go further out or drive around until their phone updates them on a pickup. No idea how much difference this makes in terms of pollution overall, however.

  • avatar
    pmirp1

    I remember couple years ago, the late summer/fall before pandemic hit, me and my wife went for a trip of a lifetime, cruise to Alaska. What beautiful country. Started in Seattle and finished in Vancouver

    Vancouver left several memories with me. One great gambling. Two full of Asians. Three, lack of Uber. What a disaster.

    When I inquired at the hotel we were staying, they said some type of taxi drivers rights or union. It was so old school. Hotel called us a taxi. We waited for what seemed like a long time, may be 30 minutes may be an hour. Probably seemed longer because you get no updates. No way to see who your driver is, track as they get closer.

    Uber and Lyft filled a gap that taxi companies were unable or unwilling to fill. Outside a few major cities, taxis are hard to find. If I left may car for service at dealer, my options were, one rent a car, two ask my wife for a ride back, three walk home. Getting taxi, forget it. Now uber in and out. I LOVE UBER.

    • 0 avatar
      Lou_BC

      @pmirp1 – Taxi companies have lobbied government to make sure that ride-hailing companies and their employees follow the same rules that taxi companies have to follow. In that respect I agree with the taxi companies. If you do the same job you should follow the same rules.

      To “ride hail” in BC, a driver must have a Class 4 driver’s license (taxi’s, ambulance, buses under 24 passengers), a business license with the city you are operating within, proper insurance, a criminal record check, routine vehicle inspections, and restrictions on how long you can drive in 24 hrs. All of that compliance cuts into the profit margins of ride-hail outfits and drivers.

      • 0 avatar
        pmirp1

        That is crazy. That essentially blows away the model for Uber and Lyft. There is a need for Uber and Lyft that Taxis don’t provide. There is not enough Taxis. The real losers are people. So you are agreeing with Taxis against people, real customers losing out in support of taxis. The few people I talked to in Vancouver (by no means am I an expert in Vancouver politics), all were for having Uber (Hotel front desk people, casino employees, and airport). The taxi business is so far out of date with technology, that they have allowed an opening to tech gig companies. They do not provide the same service. They don’t give you technology and app that Uber and Lyft do. They do not provide service in as expedient a manner. They do not provide service in as wide a region as Uber and Lyft do. They don’t keep a credit card on file so I don’t have to have a card, just my cell phone.

        • 0 avatar
          Lou_BC

          “So you are agreeing with Taxis against people, real customers losing out in support of taxis.”

          Nothing of the sort.

          I agree in as much that any business or person undertaking a fee for transport passenger service should follow the same rules.

          If you get paid to drive you are under professional motor vehicle laws. This isn’t a “city” thing. It’s provincial wide.
          A business licence is strictly municipal in origin.

          • 0 avatar
            pmirp1

            Lou_BC,

            “I agree in as much that any business or person undertaking a fee for transport passenger service should follow the same rules.”

            You are siding with Taxis because you are quoting rules in their support which bans operation of services like Uber. You easily skip over all the benefits that I said about Uber (their interactive phone app, plenty of supply, fast response, ease of payment) in support of some gibberish from your state for Taxis and say rules should be the same.

            Too bad for people. Glad Uber is available in my area, I have no sympathy for nasty Taxis

          • 0 avatar
            Lou_BC

            “You are siding with Taxis because you are quoting rules in their support which bans operation of services like Uber”

            There is NOTHING banning “ride-hail” outfits. If you want to operate carrying passengers in a commercial capacity you have to follow commercial rules.

      • 0 avatar
        el scotto

        @ Lou_BC Sir, after taking some “Mr. Toad’s Wild Ride” from the airport terminal to car rental agency, I can agree to a buses under 24 passengers license. Proper, paid and in affect insurance, enough said. Criminal Records check? File that under “Well Duh”. Vehicle inspections? Uber black kinda takes care of that. I’ve my third Red bull dude! I can drive another eight hours!

  • avatar
    NigelShiftright

    By all means, let’s nix ride-sharing and bring back the metered/medallion, supply capped, taxi system.

    Your local elected officials (and their kids’ college funds) will thank you. So will their friendly consultants Vito and Nunzio.

  • avatar
    Rick T.

    “…it hinted that central planning and shrewd policy decisions…”

    LOL. When have those two ever happened at the same time?

  • avatar
    CoastieLenn

    I moonlighted as an Uber driver for about a year and a half. It was fun, but I immediately recognized a problem that, should you voice that concern in a collective setting of drivers, you’ll immediately get head bashed. Lyft and Uber do not limit the number of drivers in each geographic area. They’re both equally hellbent on the fastest response times to passengers, and they flood their markets with drivers. This causes excessive amounts of vehicles on the road during any driving time, but the number of people seeking to use the services might not actually support having that number of drivers. Since neither outfit pays their drivers if they’re not giving someone a ride actively, there’s no harm or foul for the ride hailing service.

    I see one way to help the problems that these services are creating would be to limit the number of livery licenses each service is allowed to endorse in the states that require them. Most of the cities that suffer from the highest congestion rates require livery licenses and insurances for drivers to operate under Lyft or Uber’s umbrella, just as it would a taxi driver. From what I’m seeing here locally, a car with a TAXI sign will pull up when I’ve requested an Uber. The driver has a meter, a Lyft phone, and an Uber phone. They’re maximizing their time.

    • 0 avatar
      Lou_BC

      @CoastieLenn – in my province of BC they must follow all of the rules and regulations that apply to taxi’s or any “professional” i.e. fee for service transportation service. That has been tantamount to a blockaide of their services since they cannot compete if driver’s have to carry a proper “chauffeur’s” licence, insurance and business licences.

      • 0 avatar
        CoastieLenn

        @Lou: I know here in Honolulu (and NYC IIRC), if you drive for a ride hailing service, you’re required to have a livery license but it does not stop them from performing the functions of all three services at the same time (taxi, Uber, and Lyft). The driver in my example that showed up in the Taxi- he said that when he got the ping from Uber, he turned off Lyft and his fare meter (whatever that has to do with the Taxi, IDK), and once I exit the vehicle, he would turn them all back to active for the next service ping.

        I stated my personal identification of one of the problems because at any given moment, there will be 200 drivers on Uber all around Oahu (not counting Lyft or taxis), all competing for the same small pool of riders, so those drivers are just puttering all around the island hoping to be in the right place at the right time when that person needs a ride. It’s equal parts smart and insane.

        • 0 avatar
          Lou_BC

          @CoastieLenn – I do see the occasional “sub-contractor” with their own car working for a taxi company. In that circumstance (depending on their taxi contract), I can’t see any reason why a driver couldn’t do that sort of thing.

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