How can you design a roadway to reduce heat island effects?

1 Use cool pavements

Cool pavements are materials that reflect more sunlight and emit less heat than conventional pavements. They can lower the surface and air temperatures of roadways, and reduce the need for cooling energy in nearby buildings. Cool pavements can be made of porous asphalt, concrete, or pavers, or coated with reflective sealants or paints. Cool pavements can also improve stormwater management, reduce noise, and enhance safety and comfort for pedestrians and cyclists.

2 Increase vegetation

Vegetation can provide shade, evapotranspiration, and carbon sequestration, which can help cool down roadways and mitigate heat island effects. You can increase vegetation along roadways by planting trees, shrubs, grasses, or flowers, or by creating green roofs, walls, or medians. Vegetation can also improve air quality, biodiversity, aesthetics, and mental health. However, you should consider the maintenance, irrigation, and fire risks of vegetation, and choose native and drought-resistant species.

3 Optimize geometry

The geometry of roadways can affect the airflow, sunlight exposure, and heat exchange in urban areas. You can optimize the geometry of roadways by designing them to be narrower, curved, or staggered, rather than wide, straight, or parallel. This can reduce the surface area and albedo of pavements, create more shade and turbulence, and enhance the natural ventilation and cooling. You can also avoid building roadways in low-lying areas or near water bodies, where heat can accumulate.

4 Integrate renewable energy

Renewable energy can reduce the greenhouse gas emissions and fossil fuel consumption associated with roadways, and provide clean and sustainable power for urban needs. You can integrate renewable energy into roadways by installing solar panels, wind turbines, or piezoelectric devices along or above them. These devices can generate electricity from solar radiation, wind, or vehicle pressure, and feed it to the grid or to nearby facilities. Renewable energy can also reduce the dependency on external power sources and increase the resilience of roadways.

5 Promote alternative modes

Alternative modes of transportation, such as public transit, cycling, or walking, can reduce the traffic volume and congestion on roadways, and lower the heat and pollution emissions from vehicles. You can promote alternative modes of transportation by designing roadways that accommodate and prioritize them, such as by providing dedicated lanes, paths, or signals, or by implementing traffic calming measures, such as speed bumps, roundabouts, or chicanes. Alternative modes of transportation can also improve the health, mobility, and equity of urban residents.

6 Monitor and evaluate

Monitoring and evaluating the performance and impacts of roadways can help you assess the effectiveness of your design strategies and identify the areas for improvement. You can monitor and evaluate roadways by using sensors, cameras, or drones, or by conducting surveys, interviews, or audits. You can measure the indicators such as temperature, humidity, air quality, energy consumption, traffic flow, safety, and user satisfaction. You can also compare your results with the baseline or the best practices, and adjust your design accordingly.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?