S.8 Leverage points for system change

This is often an easy, but weak leverage point. It involves changing specific numerical values within a system, such as speed limits, bus fares, or fuel taxes. For example, the city could raise parking fees to discourage car use (Figure 4). These changes influence behaviour by changing incentives and restrictions, but do not transform the way the system operates.

Figure 4. Changing parking fees is a leverage point for addressing traffic congestion. (Credit: Egor Karamov)

Buffers are extra capacity that help systems absorb sudden shocks and adapt to change. They add short-term stability and flexibility. For example, adding extra buses (Figure 5) during peak transportation hours helps people get to their destinations on time, improving the way the system functions. But extra buses don’t prevent traffic congestion in the first place, so deeper systems change may be needed to really fix the problem.

Figure 5. Buffers, like extra buses during peak transport hours, can improve the stability and flexibility of a system. (Credit: Abasiakan)

Changes to infrastructure can make it more efficient or easier for resources, people, and goods to move through a system. A city may consider building roads, bike lanes, or subways to ease traffic congestion. While infrastructure changes may help, they are expensive and can backfire. For example, if driving remains easy and cheap, more roads may actually attract more cars—an effect called induced demand. This effect is related to Jevons paradox discussed in Section S.9.

Figure 6. Changing stock and flow infrastructure can temporarily relieve the pressure on a system, but can also worsen the behaviour it's trying to fix, as is often the case with road building. (Credit: Jim Baker)

Delays occur when a system takes time to respond to problems. Shortening delays helps systems adapt faster and prevent problems from worsening. For example, if it takes ten years to build a new subway line to relieve traffic congestion, a city may need a temporary solution to ease the pressure while waiting, such as more buses and separate bus lanes. 

Figure 7. Adding temporary bus routes and lanes can speed up the move to public transportation when there are delays to constructing subways or tram routes. (Credit: Zeeshaan Shabbir)

Balancing feedback loops stabilise systems by adjusting behaviour in response to change. Balancing feedback prevents extremes and reduces the need for constant intervention. Congestion pricing provides balancing feedback. When traffic increases, drivers pay higher fees to use the roads, and so may choose to use public transport or drive at other times. This feedback adjusts demand to avoid traffic congestion, improving system efficiency.

Figure 8. Balancing feedback, like congestion pricing that raises prices for car travel during peak hours, can reduce traffic. (Credit: Metropolitan Transportation Authority, Wikimedia Commons)

Reinforcing feedback loops amplify system changes in a direction over time. Beneficial reinforcing feedback should be encouraged, and damaging reinforcing feedback stopped.

A bike-sharing program creates beneficial reinforcing feedback. As more people cycle, biking becomes visible, encouraging others to join. Over time, this shifts social norms and reduces traffic.

Car dependency is harmful reinforcing feedback. More drivers lead to roads and businesses designed for car use. People live farther from core services, making other transport options even less convenient. To break this loop, cities can redesign streets to support alternative transport, setting off reinforcing feedback in the opposite direction.

Figure 9. Easy-to-use bike sharing programmes can encourage more people to ride bikes instead of driving, setting off reinforcing feedback loops through social norms. (Credit: Max Avans)

Information flows shape how people make decisions. Accurate, timely data helps systems run smoothly, while missing or misleading information can worsen problems.

In transport, real-time data on public transport timing and capacity helps travelers choose better routes and reduce congestion. If people know a train is delayed before leaving home, they may take a bus instead, preventing overcrowding.

Figure 10. Real-time transport information can help people make better choices about their transportation options, reducing traffic.

Rules shape how a system works by setting limits, incentives, and priorities. Changing the rules can shift behaviour and resource use. For example, a city could create bus-only lanes (Figure 11), giving public transport priority over cars. Faster, more reliable buses encourage more riders, reducing congestion and pollution. 

Figure 11. Changing the rules of the system, like creating bus-only lanes in traffic, can change the priorities and incentives in a system, reducing traffic. (Credit: Balvir Singh)

Self-organisation lets systems adapt without central control. With freedom and resources, people create solutions that fit their needs, making systems more flexible and resilient. Examples include local initiatives like community-run shuttles or ‘bike buses’ (Figure 12) where large numbers of children ride to school together, supported by adults. These innovative grassroots solutions often get results that top-down planning cannot. For more on community-led action, see Topic 4: Commons.

Figure 12. The ‘bike bus’ is a community-led initiative to help young people bike to school safely. (Credit: ICTA-UAB)

A system’s goal shapes its rules, infrastructure, and priorities and direction. Changing the goal can transform how the entire system operates. Most transport systems prioritise moving cars, rather than focusing on the needs of people. If a city shifts its goal to clean air and easy mobility, it will invest in public transport, biking, and walking instead of expanding roads. This change reshapes policies, infrastructure, and behaviour to serve more people, not just vehicles.

Figure 13. Many cities are converting streets into pedestrian zones, like this one in Almaty, Kazakhstan, creating safer and more pleasant streets for a larger number of people. (Credit: Алексей Тараканов, CC BY-SA 2.0)

Mindsets and paradigms shape how people see the world, defining what is seen as normal, possible or desirable. Changing mindsets can bring deep, lasting change. If people see cars as the only practical transport, they resist limits on driving. But if they view streets as shared spaces, they may support walking and cycling policies. In the 1970s, Dutch mothers shifted mindsets by protesting dangerous car-filled streets, demanding safer spaces for children. Their activism led to urban planning changes with incredible cycling infrastructure and healthier cities.

Figure 14. Dutch mothers, concerned about their childrens’ safety, led a powerful protest movement that changed views on who should have priority on the streets. (Credit: Bert Verhoeff, public domain)

Transcending paradigms means questioning assumptions and redefining problems, allowing entirely new ways of thinking and designing systems.

Many cities try to reduce traffic while assuming driving is necessary. A deeper shift asks, “How do we design places where people don’t need to drive?” This idea shapes the 15-minute city, where homes, schools, and shops are within a short walk or bike ride (Figure 15). Cities like Paris are redesigning streets to make this vision real, replacing car dependence with liveable neighbourhoods.

Figure 15. The 15-minute city concept is helping urban planners transcend car-centric planning paradigms to design cities for people. (Credit: moveBuddha via The Urbanist, CC BY-SA)