ESG Program

Learn about our environmental, social, and governance program, and how we bring those values to life with green bonds, sustainable projects, and more.

About Our Program

CTA is environmentally conscious provider of public transit—a service which, itself, plays an integral part in community being a greener, more sustainable one.

We’re committed to enhancing the quality of life of our customers, neighbors and employees through reduced regional emissions, improved energy efficiency, increased recycling and other best practices in resource conservation.

We strive to reduce our own impacts through efforts in the following areas:

 Sustainable transportation

The CTA plays an important role in reducing vehicle emissions in the Chicago region by replacing automobile trips, reducing traffic congestion and enabling compact development. By providing high-quality service for around half-a-billion transit rides per year, we strive to make regional transportation patterns more sustainable.

 Clean vehicles

We've achieved significant emissions reductions from our rail, bus and support fleets through advanced vehicle technologies and alternative fuel sources.


Our fleet of about 1,500 rail cars carries about half of all our riders.

  • Electric rail is a highly efficient motorized transport mode, operating on low-friction steel rails.
  • CTA has begun putting a new family of ‘L’ cars into service, known as the 5000 Series. These railcars are equipped with an innovative braking system that can transfer electricity back to the third rail, supplementing power to nearby CTA trains.
  • In April 2017, a report was produced following a study on how implementing a Wayside Energy Storage System (or WESS) would impact the CTA Red Line. Read the Red Line WESS report.


  • We have a fleet of nearly 1,900 buses, which, thanks to new technology and recent replacement efforts, have been becoming more energy efficient and produce fewer emissions.
  • We converted our entire bus fleet to ultra-low sulfur diesel in March 2003, well before the US Environmental Protection Agency mandated its use in October 2006. All buses delivered since 2007 have clean-diesel engines and particulate filters that meet EPA emissions standards.
  • Emissions of key pollutants from our bus fleet decreased thanks to retrofitting and replacement work, including nitrogen oxides, hydrocarbons, carbon monoxide and particulate matter.
  • We’ve employed technologies at garages for our hundreds of hybrid buses that allow buses to keep warm and minimize engine idling during cold winter months.
  • Following a successful year-long operation of Chicago’s first two all-electric buses, we announced in 2016 plans for the nation’s second largest transit agency to purchase between 20-30 additional all-electric buses in the next few years,
  • In 2011, we received federal Congestion Mitigation and Air Quality Improvement Program (CMAQ) grants for installing two bus fuel-efficiency technologies: $900,000 for Topodyne transmission software and $6.2 million for all-electric cooling fans.
  • Our support vehicle fleet includes hybrid-electric SUVs, sedans and pickup trucks, vehicles that can run on 85% ethanol gasoline, and some vehicles that run on clean-burning compressed natural gas.

 Multimodal integration

CTA's Bike & Ride program was established to improve bicycle access to bus routes and rail stations. We continue to pursue bike-friendly initiatives to help reduce vehicle emissions and promote healthy transportation habits. 

  • Each CTA bus can accommodate up to two bicycles on front-mounted bicycle racks during all operating hours.  A demonstration bus-mounted bicycle rack is available outside of CTA headquarters at 567 W. Lake Street. 
  • Bicycles are permitted on CTA trains every weekday (except from 7 am to 9 am and 4 pm to 6 pm, and in cases of or where extreme crowding is anticipated).
  • Over the years, we’ve worked with car-sharing companies to make it easy to get between car sharing and public transit, reducing private vehicle ownership and dependency.
  • We work regularly with the City of Chicago and other municipalities we serve to further transit-friendly development, improve pedestrian access and connections with our services and destinations.

 Efficient facilities

  • Through recent renewal and renovation programs, we’ve retrofitted subways and stations with more energy-efficient lighting, including LED lighting.
  • We’ve installed green roofs, which conserve energy, reduce stormwater runoff and reduce urban heat island effects, at our headquarters and at a recently upgraded substation.
  • We’ve replaced over a dozen slow-closing doors at various vehicle maintenance facilities, which save thousands of dollars in heating costs annually.
  • Several track lubrication machines across our system are powered by solar energy, eliminating the need to run potentially miles of powered cable for certain machines.
  • In 2013, we began installation of 55 high-capacity, environmentally friendly in-ground vehicle lifts for servicing the bus fleet.
  • In 2012, our headquarters was awarded the Leadership in Energy and Environmental Design (LEED) Platinum Certification, an upgrade from the Gold Certification we received in 2007.


We purchase recycled materials where possible to reduce overall environmental impact. In addition, our internal recycling strategies and platform recycling bins help divert waste that would otherwise end up in landfills.

  • We recycle engine oil and antifreeze at each of our seven bus garages and lead-acid batteries at our twelve rail yards. Additionally, we recycle metals from bus and rail shops, and plastic components from CTA-owned bus shelters.
  • We employ fluorescent bulb crushing machines at a number of maintenance facilities to process spent bulbs into recyclable glass fragments while capturing hazardous mercury vapors.
  • We use bus and rail car washer systems that have built-in water recycling capabilities, saving up to 500,000 gallons of water in an average week.
  • Recycling bins for paper products, glass, plastic and aluminum containers, dry-cell batteries and plastic bags are available at various CTA office locations.
  • Newspaper recycling bins are provided for CTA customers on more than rail station platforms at most stations.