What are nodes and corridors?

City planners, urban design professionals, engaged citizens, and planning documents talk about encouraging redevelopment near transit stations and along main streets as “nodes and corridors planning.” In Calgary, since 2009, the City’s Municipal Development Plan has encouraged “development land use change along a series of identified within a framework of nodes and corridors.”

In an ideal scenario, this approach would support local businesses, make transit more effective, and be a more efficient use of infrastructure. Additionally, it may be viewed as more desirable politically because the biggest changes tend to be along the edge of neighbourhoods, where fewer residents may exist to object to the growth. However, narrow nodes and constrained corridors that switch quickly to low-density houses cause problems for current and future residents.

This approach has been frequently discussed in Calgary through many recent local area planning initiatives, the controversial Guidebook for Great Communities, and the ongoing base residential zoning discussion.

This method of targeted growth has been used by other cities in Canada including Vancouver, Edmonton, and Toronto, among others. Within Calgary, examples of the nodes and corridors approach include 16 Avenue N, 33 Avenue SW, and 9 Avenue SE. In addition to being major transportation corridors through their respective communities, the above Calgary street examples have been identified as “main streets” – where the City has a vision of creating a place “where citizens come together.” 

Challenges and limitations

In principle, the nodes and corridors approach to city planning sounds ideal; it puts high-density growth at the edge of existing communities, where there is better access to transportation infrastructure and fewer people to be impacted. However, there are some limitations and unexpected consequences if it isn’t done right. There are issues associated with mental and physical health impacts on residents located in these developments, the challenge of transitioning into the lower-density form of many existing neighbourhoods, and the issue of dollars and cents.

Most recently, Vancouver has found that pushing growth to the periphery of communities has resulted in a sea of detached houses being located immediately next to large tower blocks, using the multi-family and higher-density buildings to “buffer” the single-detached homes a block away from the noise, sights, and environmental conditions present along a major road. 

Over and above desirability, there are also concerns around the health impacts of living near major roads including a decrease in life expectancy and an increased risk of developing dementia. There is also new research showing that those living along major roads and developments near core transit hubs are exposed to higher levels of noise pollution than people further away, further impacting overall health and enjoyment.

Exposure to vehicle exhausts and, more broadly, air quality in general, has also been shown to be worse along major corridors and can be extremely detrimental to the health of those living nearby. Locating more people along busy transportation corridors, without appropriate mitigation efforts, may result in adverse health outcomes and an increased strain on healthcare services.

Further adding to the potential health effects is the distance between main streets and parks and other community amenities such as schools, which are generally located in the centre of neighbourhoods. The often rapid growth of a community as a result of a single development may put strain on these existing services, especially when thinking about schools and healthcare facilities. This extra distance from the edge of communities to key facilities and space decreases their accessibility for new residents

Looking forward

Regardless of the driving force behind it, Calgary is experiencing rapid population growth with estimates of more than 21,000 additional neighbours moving to Calgary each year, with the City of Calgary estimating population growth in 2023 at 42,000 people. This rapid growth, combined with development rates that aren’t keeping up, is driving house prices rapidly up and causing affordability issues across the housing spectrum. 

If we look at the local example of the Midtown Station development, proposing to house approximately 11,000 residents, the timelines associated with these developments become apparent. With a land-use change submitted in 2019 and only now, in 2024, coming to public hearing, it is expected that this development will conclude its build out in 2047. Averaged out over the construction timeline this equates to approximately 480 homes a year – a far cry from addressing the housing required for the minimum 21,000 people each year. If we expect 2023 growth rates of 42,000 people/yr becoming Calgarians, we will need more than 100 more of these projects to be undertaken throughout the Midtown development to meet growth pressures. This simply is not feasible, even if the majority of current city-identified transit-oriented developments were to be initiated today.

The development timelines on the nodes and corridors approach to densification are both slower and more capital intensive. It concentrates the power in the hands of larger developers, and extends over multiple decades, offering little relief to the housing market now. To address the need for more homes now, and provide a more equitable approach to housing, we cannot look at building along main roads exclusively. We need to begin looking at adding gentle density across the entire city. Additionally, when viewing the outcomes through the lenses of equity, affordability, and housing choice, the nodes and corridors approach misses the mark.

At its best, growing along major thoroughfares is only a partial answer to housing challenges facing a growing Calgary. At worst, it can be viewed as a form of segregation and classism. Accordingly, it needs to stop being viewed as a silver bullet. We need gentle density across the entire city along with larger developments to address the housing shortage we face.