GCT Guide to Sustainable Public Mass Transportation

Environmentally Friendly and Efficient Public Mass Transit

Electric Bus
Electric public transit is clean when the charging source is renewable energy

Sustainable Public Transit


Gct Guide To Sustainable Public Mass Transportation
A battery-electric bus charging

Mass public transit options reduce greenhouse gas emissions (GHGs) from the transportation sector, help to produce numerous other environmental benefits, and help to create urban centers of productivity.

As far as carbon-based transit, the amount of emissions per passenger-mile is greatly reduced with any type of public mass transit compared to the use of conventional fossil fuel-dependent private cars.

Electric public transit options are low-carbon, sustainable solutions that become cleaner the greater the level of renewable energy in the electricity mix on the grid where the electric vehicle (EV) charges.

An electric public transit vehicle is completely zero-emissions when charged with an entirely renewable energy-fed electricity grid, as are the cases in Norway and Iceland.

Fuel and energy technologies that represent widely developed global trends in modern, cleaner, environmentally sound, cost-efficient, and energy-efficient mass transit include:

  • - electric transit, such as battery-electric buses; as well as other (privately-owned) electric transit vehicles (electric taxi fleets, electric shuttles, etc...)
  • - electric light rail  (streetcars, trolleys, and trams)
  • - commuter rail (often electric), rapid transit rail (usually electric), and high-speed rail (also an electric transit option)
  • - biofuel (biodiesel and bioethanol vehicles, such as biodiesel buses); and buses that run on other low-carbon fuel blends (such as bio-liquified natural gas blends and other biofuel blends)
  • - electric-biofuel hybrid vehicles, hybrid electric-biodiesel buses, as well as a wide range of other hybrid vehicles 
  • - bus rapid transit (BRT)
  • - *hydrogen fuel cell vehicles (*not widely developed, still mostly in research and development, with some limited deployment)

The higher the quantity and quality of sustainable public mass transit options, the greater the opportunity and incentive for people to look beyond traditional internal combustion engine (ICE) vehicle use.

In order to address transportation efficiency and emissions there are a wide variety of sustainable mass transit options available today.

Below are quotes about emissions from the transportation sector -

"Transportation [is responsible for over a quarter of U.S. greenhouse gas emissions] – Greenhouse gas emissions from transportation primarily come from burning fossil fuel for our cars, trucks, [buses], ships, trains, and planes." 

[QUOTE FROM  - epa.gov/ghgemissions/sources]

"Transport accounts for around one-fifth of global carbon dioxide (CO2) emissions [and more than one-third of CO2 emissions from end-use sectors]."

[QUOTE FROM  -  ourworldindata.org/co2-emissions-from-transport]

Below are details on some cleaner, greener, low carbon, low and zero emission transportation alternatives to conventional fossil fuel modes of transit>>>

Low and Zero Carbon Modes and Fuels for Sustainable Public Transit


Ebus 1
A battery-electric bus charging

Modern mass transit systems include vehicles using various clean energy technologies that are an ever-expanding part of the global mass transportation sector. One significant modern sustainable advancement has been the electrification of transportation.

100%-electric and hybrid buses, electric light rail, private EVs, and other cutting-edge electric mass transit technologies, are all exciting advances in sustainable transit globally.

It must be noted that electric vehicles, through their electric motors and drive systems, produce zero emissions.

EbusAs long as the energy source for the given electric transit option is based on renewable energy (whether it's mass transit like electric buses, trams, and light rail, or private transit like individual EVs), the transportation source remains entirely zero emissions. When an electric transportation option is powered by a municipal grid with fossil fuels in the energy mix, the electric transit option is still responsible for emissions.

Electric vehicles are still fossil fuel-intensive resources to the extent that the power plants that provide electricity to ultimately power the vehicles are fossil fuel-intensive. This is why it remains essential for municipal grids to be powered by renewable energy sources like wind and solar, to the greatest extent possible.

As far as a complete departure from oil dependency, the world must embrace sustainable mass transit technologies now available that run on electricity and/ or renewable energy sources, such as biofuels.

There continues to be a segment of the transportation sector that is not yet ready, for one reason or another, to electrify completely. In the meantime, as the world transitions public mass transit away from fossil fuels, there are clean, green, low-emission fuel options for public buses and other mass transit vehicles.

Biofuels (bioethanol and biodiesel) are low-carbon, cost-effective, and cleaner fuel options compared to petroleum used by ICE vehicles. Due to the large contribution made by fossil fuels to global warming, biofuels are preferable alternative fuels in order to lower GHGs from the transportation sector.

Biofuels are derived from biomass; such as agricultural feedstocks, organic material such as plants, forestry residues, and waste streams, or kitchen oil and lipids (in the case of biodiesel). Biofuels do have carbon emissions associated with their use, however, the net carbon emissions of biofuels are much lower than petroleum.

Biofuels are all originally derived from organic sources of carbon sequestration. Carbon is sequestered by the organic biomass used to produce the biofuel; before that carbon is released in the combustion process of a vehicle's internal combustion engine (a net carbon-neutral lifecycle).

First-generation biofuels are derived from food crops (such as corn, sugarcane, soybean, and wheat). Second-generation biofuels are derived from cellulosic biomass; primarily non-food agricultural crops, agricultural and forestry residues, and organic waste streams. Third-generation biofuels are derived from algae.

2nd and 3rd-generation biofuels represent a wholistic sustainable solution, as crops needed for the world's food supply are not used to produce the fuel.

See these articles on 2nd and 3rd-generation biomass:

Cellulosic Biofuel - Fuel Solutions

Algae: The Future of Biofuel

Please also see Anaerobic Digestion - A Proven Solution to Our Waste Problem - for more on waste-to-energy, putting waste to good use in creating renewable energy.

Biofuel blends are cost-efficient, environmentally-friendly sustainable fuel alternatives for mass transit vehicles dependent on fossil fuels. Biofuel blends often refer to biofuels blended with petroleum, although 100% biofuel blends are also available; which are entirely based on renewable biomass as the fuel source.

Many biofuel blends, especially those with high levels of organic renewable fuel content, provide GHG reductions of at least 50% compared to fossil fuels; and also result in the benefit of fewer air pollutants, beyond the GHG reduction. Biofuel blends tend to be cost-competitive with petroleum, or come with a relatively small "green premium" (the cost of producing and using a more environmentally-friendly fuel).

Biofuel blends, both ethanol and biodiesel blends, are some of the most common low-carbon fuel sources for sustainable transit worldwide.

Biofuels are used in many types of public mass transit and hybrid vehicles globally (such as hybrid cars, trucks, and buses designed to run on biofuels). 

Gct Guide To Sustainable Public Mass Transportation
A biodiesel bus

Some vehicles can run on biofuels with minimal modification to the vehicle's internal combustion engine (depending on the type of vehicle and the type of biofuel). Others, such as biodiesel buses, have been designed or converted to run on biofuel blends.

Organic biomass can be replenished readily to create biofuels for use in sustainable mass transit. For example, biodiesel blends are used in biodiesel buses and in hybrid electric-biodiesel buses.

Other alternative cleaner low-carbon fuel options include bio-liquefied natural gas (bio-LNG), bio-compressed natural gas (bio-CNG), and bio-LNG/ CNG-electric hybrids. Bio-LNG and bio-CNG are both renewable fuels, made from organic biomass (bio-LNG stands for liquified natural gas from biological origin).

Bio-LNG fuel blends are popular options for low-carbon sustainable transit worldwide (especially heavy-duty transportation and shipping). Bio-LNG is a biofuel made from organic waste streams; which are transformed into biogas through the anaerobic digestion process. The biogas is then liquified in a cooling process, which reaches temperatures of -162°C.

Gct Guide To Sustainable Public Mass Transportation
A hydrogen fuel cell bus

Hydrogen is used in demonstration transit projects in several countries in Europe (please see CHIC; H2BusEurope), in the form of hydrogen fuel cells for buses. One great benefit of hydrogen fuel cells is that they produce absolutely zero emissions, with water vapor as the sole by-product.

Nations of the entire world must embrace low and zero emission sustainable transportation technology like hydrogen.

Gct Guide To Sustainable Public Mass Transportation
A hydrogen fuel cell bus

The use of hydrogen for transportation worldwide is rolling out little by little, with applications in places from California to Norway to Asia. Hydrogen fuel cells for shipping vehicles, and hydrogen for long-haul trucks, remain in the research and development stage, with limited deployment for demonstration projects.

Hydrogen fuel cell cars are expensive and have limited refueling options, but Japan plans to have 200,000 hydrogen cars on the road by 2025 (along with over 300 hydrogen filling stations). China aims for 50,000 hydrogen fuel cell vehicles (FCVs) on its roads by 2025.

Electric Rail


Gct Guide To Sustainable Public Mass Transportation
SkyTrain (automated electric urban rapid transit rail) in Vancouver

In addition to biofuel buses, another sustainable mode of public mass transit is rail. Particularly clean and efficient are electric urban light rail, electric urban rapid transit rail, and electric commuter rail. Light rail is energy-efficient and cost-efficient; and has low maintenance needs and low energy demands.

Electric vehicles as public mass transit options in world cities often come in the form of electric and electric-hybrid buses.

Another popular electrified mode of mass public transit globally is electric light rail (tram, streetcar, trolley, or other light rail). EVs for sustainable mass transit can also be in the form of electric commuter rail, electric rapid transit rail, electric high-speed rail, electric taxis/ shuttles/ vans/ other private cars (and even some electric ferries/ ships).

All forms of electric transit will get more sustainable as municipal and national grids continue to be supplied with increasing shares of renewable energy. In fact, greater shares of renewable energy are absolutely needed on grids worldwide in order to ensure the sustainability of electric transit.

Environmental benefits of electric rail (and other electric mass transit) include the reduction of carbon dioxide, as well as the reduction of other GHGs and pollutants caused by ICE vehicle traffic. Traffic congestion is greatly reduced in any urban environment with light rail, and ultimately light rail systems can replace highways.

Electric rail creates jobs both by producing a new source of capital, using new technologies, and creating employment opportunities with the mass transit itself and also by creating new, busy economic urban centers.

Not only does electric rail effectively replace the use of fossil fuels, but the development cost of light rail systems is about half that of building freeways.

Please see:

Benefits of Hybrids, Plug-in Hybrids, and Electric Vehicles

Please also see:

Solutions to Fossil Fuels

High Speed Rail
A high-speed rail line in Spain

Another form of sustainable mass transit that can (optimistically) dominate the world's future market for low-carbon transit options is high-speed rail.

High-speed rail runs on electricity and is an excellent eco-friendly alternative to flying to travel long distances.

High-speed rail greatly reduces GHGs per passenger-mile compared to planes.

With pioneering high-speed rail lines in Japan, as well as more recent additions throughout Asia and Europe, there is every reason to hope that high-speed rail can gain momentum to serve transit needs globally.

If the on-again, off-again, extremely slow roll-out of high-speed rail in California is any indication, however, the world might just have to make due for now with the many various Asian and European high-speed rail lines.

Bus rapid transit in Curitiba, Brazil
Bus rapid transit in Curitiba, Brazil

Bus Rapid Transit (BRT), and Public Transit in Curitiba and London


An exciting sign of progress in clean, low-emission, sustainable mass public transportation is the further development of electric, alternative low-carbon, biodiesel/ ethanol-fueled, and hybrid buses (especially those that run on bus rapid transit - BRT - networks).

BRT networks represent remarkably high-quality transit developments. BRT represents a revolutionary global trend in mass transportation, streamlining bus transit networks to increase the efficiency of bus systems.

BRT networks have features such as dedicated express lanes, innovative methods for passengers to easily purchase bus fares off-board, traffic signal priority, and efficient loading/ unloading passenger platforms in high-quality stations.

These advanced features of BRT networks also serve to increase transit quality, traffic safety, as well as reliability and convenience of public transit. Some BRT networks also have trip-planning features such as live arrival and departure times with live schedules.

BRT buses also have advanced features such as highly efficient, high-capacity, longer buses, and a large share of low-emission vehicles, with frequent and on-time service.

BRT networks reduce travel time and reduce GHGs and other local pollutants from public transit (especially when run on alternative low-carbon fuels).

Electric, biofuel, and other low-carbon hybrid buses are effective means to reduce GHGs in public transit. The positive sustainable impact of these bus systems is improved markedly when bus routes are developed to be widely accessible throughout a city and are incorporated into BRT networks.

Examples of successful, highly efficient mass public transit, particularly in terms of clean, green bus utilization with high rates of ridership, are in London; and another is Curitiba. Curitiba has its fair share of biofuel and hybrid buses in the city's bus fleet, and also has one of the world's best examples of a successful BRT network in a metropolis.

Curitiba, Brazil represents an early adopter of BRT systems and a pre-eminent success story in public mass transit. Curitiba exemplifies the ideal use of a bus system to maximize sustainable public transit options for a city; a successful BRT system. 

The Curitiba BRT system is one of the greatest examples of successful mass transit in the Southern Hemisphere. The bus system in London is another great example of successful mass transit in a metropolis, this time in the Northern Hemisphere.

Today, a significant number of London buses are all-electric, run on low-carbon fuels, are hybrid diesel-electric, or other low-carbon hybrids. All new double-decker buses in London will be electric, or low-carbon hybrids, and will focus on only running the greenest, cleanest buses. In central London, all single-deck buses will generate zero exhaust emissions.

By 2037 at the latest, all 9,200 buses across London will be zero-emission buses.

Please see>>> 

Vancouver: Alternative Transit Capital of North America

Green City: Bus Rapid Transit and Urban Planning in Curitiba

Green City: London (and Mass Transit in London)

please also see:

Clean Hydrogen in European Cities (CHIC); H2BusEurope