On Transit and Climate


Urban transit is important for those who lack access toautomobiles. But the history of the last four decades shows thattransit cannot and will not play a significant role in savingenergy or preventing climate change.

Forty years ago, American cities were choked with air pollution,so Congress passed the Clean Air Act of 1970 and created theEnvironmental Protection Agency (EPA) to administer the law. TheEPA adopted two strategies to reduce pollution. First, it requiredautomakers to make cars that polluted less. Second, it alsoencouraged cities to promote transit and adopt other policies aimedat getting people to drive less.

Today, we know what worked and what did not. Automotive airpollution has declined by at least two-thirds since 1970. Thisentire decline was due to technological changes in automobiles. Farfrom responding to transit investments by reducing driving andtaking transit more, Americans today drive far more than they didin 1970.

As the late University of California (Irvine) economist CharlesLave demonstrated in the October, 1979 Atlantic Monthly,investing in transit fails to save energy or reduce air pollutionfor two reasons:

  • First, spending more money on transit does not significantlyreduce driving.
  • Second, transit uses just about as much energy as cars, so evenif we could persuade people to take transit it would not saveenergy (see http://www.theatlantic.com/doc/197910/197910).

Dr. Lave's arguments are as valid today as they were in 1979,and as valid for greenhouse gas emissions as for energy and otherpollutants. The difference between 1979 and today is that today wehave much more evidence to back up Dr. Lave's points.

Transit Investments Do Not Significantly IncreaseTransit Ridership

Transit subsidies have historically had only a trivial effect onridership. Between 1987 and 2007, annual subsidies in real dollarsgrew by 68 percent. Yet annual ridership grew by only 18 percent.While capital subsidies are sketchy before 1987, operatingsubsidies increased by 1240 percent since 1970. Yet ridership grewby only 45 percent.

More importantly, despite total real subsidies of well overthree-quarters of a trillion dollars since 1970, per-capita transitridership and passenger miles actually declined. Figure one (onpage 8) shows that per-capita transit travel declinedmore-or­less steadily from 1970 through 1995. Althoughper-capita transit usage has grown a little since 1995, it remainsbelow 1988, and far below 1970, levels.

Moreover, as figure two shows, while per-capita transit travelwas declining, per-capita urban driving grew by 120 percent.Transit carried more than 4 percent of urban travel in 1970; but itfell below 2 percent in 1990 and now stands at 1.6 percent.

My former hometown of Portland, Oregon has invested more than $2billion in light rail and streetcars. Yet this has had almost noeffect on Portland travel habits. In 1980, before Portland builtits first light-rail line, the census found 9.8 percent of Portlandurbanized area commuters took transit to work. Today, Portland hasfour light-rail routes and a streetcar line, yet the CensusBureau's American Community Survey says only 6.5 percent ofPortland commuters take transit to work.

The number of Portland-area residents taking transit to workactually declined between 2000 and 2007. These census numbers areconfirmed by a 100-percent census of downtown employers conductedby the Portland Business Alliance in 2001 through 2007. More thantwo-thirds of all Portland-area transit commuters work in downtownPortland, but this census found that 7 percent fewer downtownworkers took transit to work in 2007 than in 2001.

Transit Is Not Significantly Cleaner thanDriving

Even if more subsidies to transit could attract significantnumbers of people out of their cars, it would not save energy orreduce greenhouse gas emissions because transit uses as much energyand generates nearly as much greenhouse gas per passenger mile asurban driving. As described in my Cato Institute Policy Analysisno. 615 (https://www.cato.org/pubs/pas/pa-615.pdf), the followingdata are based on the Department of Energy's Transportation EnergyData Book, the Federal Transit Administration's National TransitDatabase, and the Federal Highway Administration's HighwayStatistics.

In 2006, the nation's transit systems used an average of 3,444BTUs and emitted 213 grams of CO2 per passenger mile.The average passenger car used 3,445 BTUs-just 1 BTU more-andemitted 245 grams of COsup>2 per passenger mile, just 15 percentmore. While transit appears slightly cleaner than autos, as shownin figure three, auto and light truck energy efficiencies haverapidly improved, while transit energy efficiencies have declined.Since CO2 emissions are proportional to energyconsumption, these trends hold for greenhouse gas production aswell.

We can expect these trends to continue. If auto manufacturersmeet the Obama administration's new fuel-economy standards for2016-even if they fail to improve energy efficiencies beyondthat-by 2025 the average car on the road will consume only 2,600BTUs and emit only about 186 grams of CO2 per passengermile-considerably less than most transit systems (figure four).

This rapid improvement is possible because America's auto fleetalmost completely turns over every 18 years. By comparison, citiesthat invest in rail transit are stuck with the technology theychoose for at least 30 years. This means potential investments intransit must be compared, not with today's cars, but with cars 15to 20 years from now.

In much of the country, the fossil-fuel-burning plants used togenerate electricity for rail transit emit enormous amounts ofgreenhouse gases. Washington's Metrorail system, for example,generates more than 280 grams of CO2 per passenger mile-considerably more than the average passenger car. Light-railsystems in Baltimore, Cleveland, Denver, Philadelphia, andPittsburgh all emit more greenhouse gases per passenger mile thanthe average SUV.

In places, such as the West Coast, that get much of theirelectricity from renewable sources, it would be wiser and morecost-effective to apply that electricity to plug-in hybrids orother electric cars that can recharge their batteries at night whenrenewable power plants generate surplus energy. As Professor Lavesaid, the "law of large proportions" dictates that "the biggestcomponents matter most." In other words, since more than 90 percentof urban travel is by auto and only 1.6 percent is by transit,small improvements in autos can be far more significant than largeinvestments in transit.

Transit has several other disadvantages as a way of reducinggreenhouse gas emissions. First, even where electric-powered railtransit generates less greenhouse gases than cars or buses, thetrains are supported by feeder bus systems that emit lots ofgreenhouse gases. While the trunk line buses that new rail transitlines replace typically run fairly full, the feeder buses thatsupport rail transit run fairly empty because many rail ridersdrive to transit stations. The result is that greenhouse gasemissions on many transit systems increase after opening railtransit lines. After opening its first light-rail line,CO2 emissions from St. Louis' transit system climbedfrom 340 to 400 grams per passenger mile, while Houston's grew from218 to 263 grams per passenger mile.

Construction of rail transit also consumes huge amounts ofenergy and releases enormous amounts of greenhouse gases. Portlandplanners estimated that the energy cost of constructing one of thecity's light-rail lines would equal 170 years worth of energysavings.

Highway construction also generates greenhouse gases, butbecause highways are much more heavily used than most rail transitlines, the emissions per passenger mile are far lower. Contrary toclaims that rail transit can carry as many people as four or morefreeway lanes, the New York City subway is the only rail transitline in America that carries more passenger miles per rail milethan one urban freeway lane mile. Outside of New York, the averageurban freeway lane mile carries 12 times as many passenger miles asthe average commuter rail mile, 7.5 times as many as the averagelight-rail mile, and 2.4 times as many as the averagesubway/elevated mile.

Further, as we tragically learned in the recent WashingtonMetrorail crash, rail transit systems must be completely rebuilt orrehabilitated every 30 years or so. The energy costs and greenhousegas emissions from such reconstruction must be taken into accountwhen considering rail transit. As a recent Federal TransitAdministration report calculated, rehabilitation of rail lines inthe nation's seven largest transit systems will cost at least $50billion-money those agencies don't have. This is just one moreindication that rail transit is not financially sustainable.

In the rare case where a transit investment really will reducegreenhouse gas emissions, the cost is exorbitantly high. McKinsey& Company says the United States can cut its greenhouseemissions roughly in half by 2030 by investing in technologies thatcost no more than $50 per ton of CO2 equivalent. Buttransit investments, if they reduce emissions at all, do so atcosts of $5,000 per ton or more.

The American Transit Model Is Broken

Transit's poor performance is symptomatic ofgovernment-subsidized transit systems. Transit agencies thattypically get three-quarters of their funds from taxpayers and onlya quarter from transit users are politically obligated to runtransit throughout their taxing districts no matter how few peoplewant to use transit. The result is that the average transitvehicle, whether bus, light rail, subway, or commuter-rail car,runs an average of only one-sixth full.

Far from being short of funds, transit agencies have too muchmoney, which they spend in the wrong places. Instead of providingeconomical transportation to users, they spend it on urbanmonuments such as light-rail and streetcar lines whosetransportation value is negligibly different from buses. Agenciesoften go heavily into debt building these lines and are alsoobligated to huge operations and maintenance costs. Almostinevitably, they suffer budget crises that force them tosignificantly curtail service.

On a passenger-mile basis, transit buses typically consume asmuch energy and emit as much CO2 per passenger mile asSUVs. By comparison, private bus companies have an incentive tofill as many seats as possible, so they typically operate half totwo-thirds full and consume little more than 10 percent as muchenergy per passenger mile as public transit buses. Between Bostonand Washington, for example, at least 14 bus companies carry morepassengers each day than Amtrak and do so using less than half asmuch energy and emitting about half as much greenhouse gases.

To make transit more environmentally friendly, we need tocompletely redesign our transit systems. This means eitherprivatizing transit systems or, at the least, operating thementirely out of user fees rather than subsidies. If states feel theneed to support people who have no access to automobiles, they cangive such people transportation vouchers that they can use on anypublic conveyances.

Transport Strategies to Reduce Greenhouse GasEmissions

At the same time, we can significantly reduce greenhouse gasemissions from automobiles without engaging in futile efforts totry to get people to stop driving. The Texas TransportationInstitute says urban congestion wastes nearly 3 billion gallons offuel each year. Simple, low-cost techniques to relieve thiscongestion can do far more to reduce greenhouse gas emissions thaninvesting more in a failed transit model.

One such technique is traffic signal coordination. A smallinvestment in signal coordination can do more to reduce greenhousegas emissions than billions invested in transit. For example, SanJose recently coordinated signals at 223 intersections, whichreduced emissions by 4,200 tons per year at a cost of about $7 perton. When the savings to motorists are counted, the projectactually saved $200 per ton of reduced emissions. Yet the FederalHighway Administration estimates that three-quarters of thenation's traffic signals are obsolete or have no coordination atall.

Congestion pricing on existing HOV lanes and all new urbanhighways will also significantly reduce congestion. Looking to thefuture, accelerated investments in vehicle-to-vehicle andvehicle-to-infrastructure communications can greatly reducecongestion and increase personal mobility while saving energy andgreenhouse gas emissions.

In short, instead of a futile effort to change Americanlifestyles, we simply need to make the form of transportation usedmost by Americans (as well as most Europeans and Japanese) evenmore efficient than it is today.

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Randal O’Toole

Subcommittee on Housing, Transportation and Community Development
Committee on Banking
United States Senate