Benefits and disadvantages of urban greenways

In my Masters research I found that nearness to nature was one of the top three reasons that individuals moved to the suburbs in Edmonton. In terms of climate change, this is not a good thing. The suburbs tend to be fairly distant from, well, everything. Grocery stores might be walkable, for some residents, and there does seem to be a high number of professional services (physiotherapy, hairdressers, etc) cropping up in community strip malls; but other commercial services continue to be a car ride away. This is why, when I read the study by Ngo, Frank, and Bigazzi (2018) on the effects of new urban greenways on transportation energy use I was a little suspicious.

Ngo, Frank, and Bigazzi did a longitudinal study looking at transport choices and associated greenhouse gas (GHG) emissions before and after the development of an urban greenway. They found that residents who lived within 300 metres of the greenway drove less. Of course residents living further than 300 metres drove more which they attributed to the increase in available car shares in the area. Wait a second, car shares? Where was this study done?

Ah, Vancouver, and not just Vancouver but a fairly central area in Vancouver. So why did the car shares make a difference, because the residents in the community were already more likely to walk (and not own cars) than many residents living in other areas and the new availability of car shares made it easier for these non-car-owning folks to drive (this was the researchers’ conclusion).

This is great on one front. I’ve had the good fortune of living near Edmonton’s river valley at times and it definitely increases the likelihood of me not driving to places like work because I could get from my home to work by using the river valley and spending less time riding on scary roads. But the trick to that was that both my home and work were close enough to the river valley that it offered me a path. If I move out to the suburbs like the people in my research that greenspace out there doesn’t help me get anywhere.

The authors claim that this is the first longitudinal study and that is awesome. What they investigated is important and I don’t doubt their conclusions for that population in that area. But it is important to remember that they aren’t generalizable. The impacts of the greenspace will depend on where it is located and what services (or jobs) might be connected to it. Doing the same study in the suburbs is likely to come out with different results.

Ngo, V. D., Frank, L. D., & Bigazzi, A. Y. (2018). Effects of new urban greenways on transportation energy use and greenhouse gas emissions: A longitudinal study from Vancouver, Canada. Environment, 62, 715-725. https://doi.org/10.1016/j.trd.2018.04.013