Three things we must do to cool our streets and cities

I was asked this week what we need to do to increase shade in our streets for walkability. Of course we need more trees and more verge gardens. Perhaps that was all I was supposed to say.

Heat and shade are on everyone’s agenda these days. Whether it’s the health, walkability, equity, economic, social or other aspect will depend on the organisation’s purpose. But it’s clear to all that we need to reduce urban heat as much as we can and find ways of adapting.

I was asked this week what we need to do to increase shade in our streets for walkability. Of course we need more trees and more verge gardens. Perhaps that was all I was supposed to say.

But…

If we are serious about addressing the urban heat and lack of shade problems, here are three things we must do.

1. Reduce speed limits

A major reason that we struggle to have enough trees in our cities is for the safety of speeding car drivers. Trees don’t have those handy bolts at the bottom that give way when a car hits them so traffic engineers understandably don’t want trees anywhere near their roads.

Reducing speed limits throughout our cities, and not designing roads that encourage speed, would free up a lot of space for more trees and allow the trees to be close enough to the road to shade it.

Reducing speed also comes with lots of bonuses for road safety both for people inside cars and those around them. See 30please, Safe Streets to School, Better Streets Australia

2. Remove slip lanes

The land taken up with slip lanes could be converted to much needed greenspace to reduce the heat of the surrounding area. You tend not to notice how big intersections are when you see them from inside an air-conditioned car.

Room for trees? Photo of Brisbane intersection from Walking for Transport

Stand at the side and see how big an area is paved at the intersections in your area. What is most important, saving a driver stopping at a red light or reducing the heat for everyone?

This also comes with the bonus for road safety. Slip lanes are very dangerous for pedestrians. Signalising them is a very expensive way to pretend they can be made safe.

3. Depaving

A lot of free street parking could be converted to provide planting space for street trees and pocket parks. Where we do need parking, there are pervious paving solutions that allow water to soak in.

Depaving is a thing and it’s happening in many places around the world - from small projects to replacing entire roads with parkland. Search and you will find lots of examples.

Need some research? Start with
Croeser, T., Garrard, G.E., Visintin, C. et al. Finding space for nature in cities: the considerable potential of redundant car parking. npj Urban Sustain 2, 27 (2022). https://doi.org/10.1038/s42949-022-00073-x

The important role of verge gardening

One of the reasons for the Shady Lanes slow method of verge gardening is that it gives you time to pause, look around, observe, experiment, have conversations, and reimagine your streets. Who uses the street and how? Are the different priorities in balance?

Some questions…

If people refuse to consider these three obvious adaptations to redress the balance so we can increase planting to reduce heat, what does that say?

Are there systemic issues or cultural issues that make these changes harder? If so, how might we begin to address that?