Electric Buses

Electric Buses

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Roadmap to bus fleet electrification

In April 2019, the Chicago City Council passed a resolution that established a commitment to complete the electrification of our entire bus fleet by the year 2040.  We're working concertedly toward this target – not only with recent and near-term electric bus deployments, but also through the development of a strategic plan that will serve as a roadmap to guide bus replacement, charging infrastructure installation, garage facility upgrades, and electric bus operations and maintenance over the next 20 years. 

Our electric bus strategic planning study launched in late 2019 and is currently underway. Through this study we'll be evaluating different potential approaches and associated infrastructure needs, service and operations impacts, costs, and timelines associated with converting our fleet of more than 1,800 buses to all-electric. The study also includes analysis of where electric bus deployment can deliver the greatest benefits to communities most vulnerable to, and adversely affected by, the health impacts of vehicle emissions.


Coming Soon: Our second order of all-electric buses

In June 2018, we awarded a contract to Proterra for the purchase of 20 new, all-electric buses, which will soon be ready for passenger service. These buses will be deployed to operate along our heavily traveled #66 Chicago bus route, which runs east/west between Navy Pier at the lakefront and Austin Boulevard on the city’s western border. 

Roll-out of the first buses along the #66 route is the first step in a larger plan to electrify all bus service along Chicago Avenue. Selection of the #66 route for all-electric bus service is based on an analysis of the air quality benefits that this service would provide in communities along the western portion of this route, where the prevalence of respiratory illnesses is among the highest in Chicago.


700-series: Our first all-electric buses

New Flyer 700-series all-electric bus

Entered into service in late October 2014, our first two battery-powered buses provide customers with a cleaner, quieter ride that reduces fuel costs and significantly decreases emissions, which means improved air quality for Chicagoland.

Deployment of these buses put us at the forefront of the industry, making us one of the first major transit agencies in the U.S. to use fully electric buses as part of daily service, year-round. What we've learned and continue to learn through the operation of these buses in Chicago will not only help shape the future of the CTA, but also the overall public transit industry in its ongoing efforts to become more environmentally friendly.


The 700-series electric buses replace two 6400-series Nova buses purchased in 2001. When comparing these two different model buses, each electric bus is expected to yield significant reductions in harmful emissions and air-borne pollutants.

  • Breathe easier. With lower harmful emissions, operating one electric bus is the equivalent of removing 23 cars from the road each year! Reduction in harmful emissions also reduces incidents of illnesses and respiratory diseases, which is valued at $55,000 annually per bus, or $660,000 over the expected 12-year bus lifespan.*
  • Did you hear? The noise produced by these electric buses is the equivalent to a human conversation.
  • $25,000. The estimated annual net savings in fuel costs for each electric bus, or $300,000 over the expected 12-year lifespan of each bus.**
  • 80 to 120 miles is the estimated distance each bus can travel on a single charge. Charging a bus can takes about 3-5 hours, which is less time needed to charge some tablet devices.
  • You saw it here first. We're among the first major transit U.S. transit agencies to test the feasibility and durability of electric buses in extreme hot/cold weather and with heavy passenger loads.
  • Helping shape the future of transit. What we learn from using these electric buses will not only help shape the future of CTA and the buses we design, but this is also helping shape the overall public transit industry in its ongoing efforts to become more environmentally friendly.

*Based on the EPA’s Diesel Emissions Quantifier Health Benefits Methodology
**When compared to the Nova 6400-series buses they replace.

Environmental impacts

Reduced emissions lead to reduced occurrences of illness, such as respiratory diseases. According to the EPA’s Diesel Emissions Quantifier Health Benefits Methodology, the reduction in particulate matter from just one electric bus is equivalent to about $55,000 in health benefits savings annually; and over the anticipated 12 year lifetime of the bus, annual health benefit savings are estimated at about $660,000 in health benefits. Reductions in other harmful emissions include:

  • Carbon dioxide (CO2): a 121-ton reduction per year, per electric bus. Over the anticipated 12 year lifetime of the bus, this equates to 1,452 tons per bus.
  • Hydrocarbons (HC): reduced by 0.0428 tons per year or 0.5136 tons over the 12 year lifespan of each bus.
  • Carbon monoxide (CO): reduced 0.310 tons annually or 3.72 tons over the lifetime of the bus.
  • Nitrogen Oxides (NOx): less 0.5938 tons per year, or 7.1256 tons over the lifetime of the bus.

Particulate matter (PM): reduced by 0.0274 tons per year, or 0.3288 tons over the 12 year lifespan of each electric bus.


The 700-series buses don't use traditional fuels; instead they're battery-operated and feature energy-efficient and more reliable electrical operating systems.  

  • Engine: The buses operate using a Siemens electric propulsion system that’s powered by rechargeable lithium ion (Li-ion) batteries. This system is currently used in hybrid applications across the transit industry, including new models of the red, double-decker buses operating in London.
  • Batteries: The Li-ion batteries are designed for the life of the vehicle, which is about 12 years. The batteries can store up to 300 kWh of electricity, and are monitored for safety and performance by a state-of-the-art battery management system.
  • Charging: A slow charging station is used to fully charge the batteries overnight. Charging a bus takes about 3 to 5 hours, which is less than the amount of time needed to charge some tablet devices.
  • Brakes: Similar to our hybrid buses and 5000-series rail cars, the electric buses also are equipped with regenerative braking systems, which capture energy released each time the brakes are engaged and store that energy to use in operating the vehicle.
  • Electric Power Steering: Unlike traditional belt-driven systems, which pull power from the engine and can affect a vehicle’s performance, the new buses feature more reliable electric power-steering systems. With fewer components than the belt-driven systems, the electric steering system won’t require costly maintenance and repairs. Also, when steering is not required, the electric motor can be shut off, which helps conserve battery life.
  • Heating, Ventilation, Air-Condition System (HVAC): The new electric heating, ventilation and air conditioning (HVAC) systems provide optimal comfort during all seasons, keeping the buses at carefully-calibrated temperatures even in the most severe weather. The electric systems are also far more efficient than the traditional belt-driven systems as they only operate when needed; and when in use, they operate at a constant, optimum speed. 


The buses were rigorously tested before being put into service, to ensure safe and reliable operation. Prior to delivery, both buses underwent rigorous testing at a facility in Winnipeg, Manitoba, to make sure they are capable of handling the harsh winter temps Chicago often endures.

Like all other buses in our fleet, the electric buses meet requirements set forth by the American Public Transportation Association (APTA). We also made sure that the performance regarding speed, acceleration and handling was equal to or better than other buses in the fleet.

Bus batteries

We know that there may be some concerns about the reliability of the buses and the use of Li-ion batteries, which have been reported to experience poor performance in extreme hot or cold temperature, battery life degradation after several years/miles traveled, etc.

The engineers and designers at New Flyer Industries, the manufacturer of the buses, and our personnel diligently worked together to address these issues and to ensure there are a number of safeguards in place to make sure these electric buses provide our customers with safe and reliable means of transportation for the life of the vehicle, this includes:

  • Higher quality, rechargeable batteries designed to last 12 years, which is the lifespan of a bus.
  • To help maintain the travel range of the buses during extremely cold conditions, each bus is equipped with an optional diesel-fired coolant heater. This helps ensure optimum cabin temperature for customers without added power consumption on the bus batteries.
  • The batteries on these buses can never completely drain. If a buses battery charge ever drops to a strength level of 8%, the motor will automatically shut down to preserve the remaining power. 
  • Each battery pack has a steel crash protection case.
  • Continuous battery management system. Whether the bus is in operation or being charged, each bus is equipped with a system that automatically disengages a battery cell with abnormal behavior to avoid any other battery cells from being possibly damaged.  


The two electric buses were purchased with funds provided through the Department of Transportation’s Transportation Investments for Greenhouse Gas and Energy Reduction (TIGGER) II and Clean Fuels grant programs and a Congestion Mitigation and Air Quality (CMAQ) grant from the Chicago Metropolitan Agency for Planning.


 Electric Buses

Our all-electric 700-series buses, the first of their kind to be added to our fleet and used as part of daily service.


Interior of Electric Bus

Interior view of one of the new electric buses. To ensure consistency in the customer experience and across the fleet, some aspects of the new bus design appear similar to the rest of the fleet. There are, however, a few new things we're testing for consideration on future bus orders.


Seating on new electric bus

One of the more subtle differences on the new buses is new, lightweight seating designed and built to withstand heavy-duty use. These seats reduced the weight of each bus about 400 lbs. compared to other seat models previously considered.


LED lighting on Electric Bus

The electric buses are also equipped with brighter and more energy efficient LED lighting. In fact, as part of our ongoing efforts to go "green", whenever possible, we're converting to LED lighting in our facilities and bus and rail vehicles.

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