When people think of climate solutions, the mind often goes to things that need be installed: Solar and wind, battery storage, building retrofits, tree planting, and carbon removal. All are essential.
Yet a powerful, fast-payback lever hides in plain sight: designing streets for safety. Safer streets cut emissions directly and acts as a force multiplier for transportation decarbonization—one of the largest sources of climate pollution in many countries and an area where progress must accelerate.
Safe streets unlock “avoid and shift,” the fastest path to lower transportation emissions. The biggest gains come first from avoiding car trips through better land use, then from shifting remaining trips to walking, cycling, and transit.
Avoiding and shifting multiply what is possible with vehicle improvements by reducing the number and length of car trips before technology even enters the picture.
Safety is the skeleton key that lets avoid and shift scale in transportation—and it delivers unusually strong returns on investment. Compared with large capital projects, quick-build safety upgrades, protected bike networks, safer crossings, and bus priority can be delivered rapidly, save lives immediately, reduce vehicle miles traveled, and unlock further climate benefits. This is not marginal action; it is a force multiplier that climate advocates should prioritize.
Bicycling and walking
Research shows that most people’s relationship with a bicycle for transportation is that they are “interested” but concerned that the risks and stress are too much. They’re open to bicyling and walking if it feels safe and convenient, but not if it feels exposed or confusing.
Perceived safety governs behavior. That means physical protection from fast traffic, lower speeds where people move, frequent and visible crossings, lighting, and predictable intersections. Where cities reduce vehicle speeds and add protected bike lanes and continuous sidewalks, injuries fall and the share of trips by foot and bike rises. As more people use these facilities, drivers expect them and everyone gets safer. This is how shift happens at scale.
Public transit
Safe streets enable transit in turn. Every rider is a pedestrian for part of the trip. If it is hard to cross to a stop, if the stop lacks lighting or a curb, or if the last block home has no sidewalk, the experience is unacceptable. Safer crossings, traffic calming on transit corridors, and priority for buses at signals make the whole trip safe and trustworthy, which builds ridership and reduces crashes at the same time.
Transit also creates a feedback loop: Per passenger mile, the mode is safer than driving for everyone. Vehicles are larger and driven by trained professionals, and each bus or train replaces many cars, which reduces conflicts on the street. Good transit also gives people who should not drive a better option. Teens, older adults, people with certain medical conditions, and anyone who is tired have a safe alternative when service is frequent and reliable.
Transit upgrades are also high-ROI: modest signal changes, dedicated lanes, and safer stop access can deliver large travel-time and safety gains at a fraction of the cost of roadway widening.
Efficient vehicles, electric and otherwise
Safe streets also enable smaller, lighter vehicles—and help end the arms race toward bigger and heavier ones. Lower-speed networks, traffic calming, and separated facilities make compact cars, neighborhood electric vehicles (NEVs), and microcars practical for everyday travel. In many jurisdictions, NEVs can operate on lower-speed streets; when those streets are designed for safety, households can right-size to vehicles that consume far less energy and pose less risk to others.
This reverses the trend toward ever-larger vehicles driven by high-speed, high-volume roads and crash incompatibility. Designing for safe, lower speeds makes small, efficient vehicles viable, which further reduces emissions, space needs, and crash severity.
And it matters even for electric: When considering the overall vehicle fleet, a proportion that is meaingfully smaller and lighter corresponds to a meaingfully lower GHG footprint. It also means fewer materials and resources for electrification are needed per vehicle, which has an additional effect in aggregate. Finally, a more circumspect average vehicle profile is safer for those traveling outside vehicle cabins, like walkers and cyclists, which in large numbers induces more of the lightest travel of all.
Compact, human-centered neighborhoods
Compact, mixed-use neighborhoods reduce daily travel needs so people can reach most essentials with short trips. A connected street network, homes near jobs and schools, and local services within a short walk or ride lower vehicle miles traveled across the entire community.
That cuts emissions and makes streets safer, because shorter trips on calmer streets mean fewer high-speed impacts. Children can reach a park without crossing a five-lane road. An older neighbor can get to a cafe without a long drive. People using mobility aids can count on accessible paths. Safety becomes part of daily life rather than a personal burden.
The wider built environment
Crucially, the same choices that make streets safer also produce a more resource‑efficient, resilient built environment. Designing for compact, walkable places concentrates activity where efficient, electrified buildings and infrastructure perform best.
Shorter distances and attached or smaller homes reduce heating and cooling loads, making heat pumps and building electrification more cost‑effective.
Mixed-use, human‑scaled districts support district energy and shared infrastructure, lower peak electricity demand, and improve the economics of rooftop solar, storage, and demand flexibility.
Denser, walkable street grids cut materials use per capita, reduce stormwater runoff with less paved area per person, and shorten utility extensions—saving public money while boosting resilience to heat, outages, and extreme weather.
In other words, safe streets do double duty: they accelerate transportation decarbonization and strengthen the broader clean‑energy transition across buildings and grids.
In sum, improved vehicles and fuels are necessary but not sufficient. Heavier vehicles can increase the harm in crashes and crowd out the space needed for people outside cars. When streets feel safe, households can right-size travel: walk for a half mile, use a bike or e‑bike for a few miles, take a bus or train for longer trips, and use a car when it is the best tool for the job. This pattern cuts emissions faster and reduces risk right away. It also reduces the scale of infrastructure and energy systems needed for full decarbonization, improving the return on every dollar invested in electrification and clean power.
The benefits of this pathway are wide and personal. Health improves when more people can safely walk or bike for short trips. Cleaner air reduces asthma and heart disease. Most important, fewer families experience the grief and lifelong injury that follow serious crashes.
Freedom expands as more people can travel without a car. A 12‑year‑old can bike to a friend’s house. An 82‑year‑old can cross to a pharmacy. A parent can let a child walk to school without fear. Households save money when they can own fewer and smaller vehicles.
Towns and cities save money when safer street designs reduce crashes and when compact, multimodal infrastructure costs less to build and maintain than endless lanes that must be widened again and again. For climate advocates focused on impact per dollar and speed of deployment, safe streets deliver exceptional returns now and set the stage for every other climate solution to work better.
Unlock the multipliers of avoid and shift with safety. Lower speeds where people live and shop. Build connected, protected networks for walking and cycling. Fix crossings to make them frequent and visible. Invest in frequent, reliable transit and safe access to every stop. Plan for mixed uses and connected streets. These steps cut emissions, save lives, expand freedom, strengthen the clean‑energy transition in buildings and grids, and save money. Safe streets are high‑ROI climate action—and a catalyst for more.
References
Dill, J., and McNeil, N. (2013). Four Types of Cyclists? Examination of a Typology for Better Understanding of Bicycling Behavior. Transportation Research Record. https://doi.org/10.3141/2387-01
Teschke, K., et al. (2012). Route Infrastructure and the Risk of Injuries to Bicyclists. American Journal of Public Health. https://doi.org/10.2105/AJPH.2012.300762
Litman, T. (2021). A New Transit Safety Narrative. Victoria Transport Policy Institute. https://www.vtpi.org/safer.pdf
Ewing, R., and Cervero, R. (2010). Travel and the Built Environment. Journal of the American Planning Association. https://doi.org/10.1080/01944361003766766
FHWA (2021). Safe System Approach. Federal Highway Administration. https://highways.dot.gov/safety/zero-deaths/safe-system-approach
IPCC (2022). Climate Change 2022 Mitigation of Climate Change. Working Group III contribution. https://www.ipcc.ch/report/ar6/wg3/
PNAS (2025). Global health and climate benefits from walking and cycling. Proceedings of the National Academy of Sciences. https://www.pnas.org/doi/10.1073/pnas.2422334122
UCLA Institute of Transportation Studies (2025). Active travel study identifies pathways for walking and cycling friendly cities. UCLA ITS. https://www.its.ucla.edu/2025/06/09/active-travel-study-identifies-pathways-for-walking-cycling-friendly-cities/
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