Urban Footpath Design for the Future

Urban centres all over the country suffer from one massive design flaw – the emphasis on roads over pedestrian paths.

The rapid growth of many of our cities has coincided with the introduction and increasing prevalence of the motor vehicles over the past 100 years. Naturally, city planners set aside roadways and parking for these vehicles, but this all too often comes at the expense of the pedestrians [1].

It is only in the last few years that city governments and planners have realized their error and began to rectify the mistakes of the past.

With the changing attitudes towards the importance of pedestrians in our towns and cities, the humble footpath is experiencing a renaissance and the dominance of cars is finally being challenged.

So what will the footpaths of the future be like and how will our city planners get us there?

Expanding Demands on the Footpath

The slow resurgence of the footpath has only come about due to the current pedestrian pathways being overloaded to breaking point [2].

Surprisingly to some, the modern world has found many uses for the traditional footpath that has expanded the demand on curbside real estate.

More and more people want to live within walking or cycling distance to work in line with the increasingly popular 20 minute suburb movement. Electric scooters and traditional bicycles for rent via smartphone applications compete for the small amount of pavement designated for pedestrians and ride sharing drivers as well as public transit needing space for drop offs and pickups [3].

This does not even take into account footpaths as community space where cafes place tables, small businesses sell products and residents interact on a daily basis [4].

A rising demand for footpaths, in conjunction with years of neglect of these public spaces means that something needs to drastically change.

‘Complete Streets’ are that solution, but you may be surprised to learn that this idea is not even that new [5].

It’s Time For Complete Streets

In 1971, Oregon became the first jurisdiction in the country to enact ‘Complete Street’ legislation. It was a simple, yet at the time revolutionary idea. It specified that all new or rebuilt streets must adequately provide for both pedestrians and cyclists [6].

The idea of Complete Streets, which at the time went against the grain of a car-centric society, has been slowly gaining momentum. Today, more than 490 jurisdictions across the nation have Complete Street legislation enacted and the number is growing continuously [7].

But what exactly is a complete street? The exact design elements can vary depending from one city to the next, but some common features include:

• Wide footpaths suitable for those with disabilities.
• Increased numbers of pedestrian crossings, overpasses or underpasses.
• ‘Traffic Calming’ measures to slow the speed of traffic, including: lane narrowing, speed bumps, angled curbs and parking and pedestrian islands.
• Accommodations for mass transit, such as bus lanes, bus pullout lanes and bus shelters.
• Dedicated and separated bicycle lanes or marked, bicycle lanes on the roadway.

For cities that want to promote healthier lifestyles through increased walking or riding, Complete Streets seem like the most obvious choice. While they are certainly needed in cities of the future, there is an environmental elephant in the room.

The Environmental Elephant in the Room

Traditional paving materials such as asphalt, pavers or concrete are impermeable and do not allow water to infiltrate into the soil naturally [8]. Not only does this damage the replenishment of groundwater, risking increased rates of subsidence, it also has knock on effects for the residents of the city and surrounding waterways [9].

A high number of impervious surfaces increase the rate and velocity of surface run-off during large rain events. Managing this runoff requires expensive stormwater drainage systems and if these are not designed effectively or with enough spare capacity, the risk of flooding is greatly increased [10].

Even if the stormwater systems can keep up with the volume of water, the runoff is often diverted to local waterways. Runoff from impervious surfaces have a much higher level of pollutants that have not been filtered via infiltration before reaching waterways [11]. The impact on local waterways adjacent to large areas of impervious surfaces can be devastating.

The good news is that with the right material choices, increased paved areas for pedestrians and cyclists can also be a positive for the environment.

Material Choice Matters

In response to the impact of impervious materials, a number of more permeable options have been developed in recent years. These include:

• Permeable Concrete,
• Permeable Asphalt, and
• Stabilized aggregates.

Both the permeable versions of concrete and asphalt are big improvements on the originals. They do allow for water to infiltrate (albeit at a less than natural rate) and maintain most of the durability of the impervious versions. However, they can be more expensive to install and maintain, lowering their appeal to city planners and landscape designers [12].

Out of these three permeable option, an aggregate stabilized with Organic-Lock™ is a clear winner. On their own, loose aggregates like decomposed granite are not durable enough for heavy foot or bicycle traffic, but with the addition of this natural stabilizer, they become far more durable and erosion resistant, while maintaining natural rates of water infiltration [13].

Paths and other walkways laid with stabilized aggregates are as close to nature a path can get while still having a hard, usable surface for pedestrians and cyclists. This type of material not only looks natural, but it is tremendously cost effective to maintain, creating a far greater life cycle cost.

The benefits of stabilized aggregates are recognized as environmentally sound by the widely used LEED environmental regulations [14]. Due to the high rates of natural infiltration, local material used in construction and long term durability of stabilized aggregates, they tick a lot of boxes when it comes to sustainability.

Pedestrians are Reclaiming the Streets

The trend in pedestrians reclaiming the streets is clear both here and across the world.

Although mistakes were made in the way our cities were designed in the past, we now have the chance to make things right and give pedestrians the space they need and deserve.

However, it is important that planners do not make new mistakes in the process. Improving and expanding pedestrian zones without considering the environmental impact of impervious surfaces would be a grave error that could be felt far into the future.

All city planner and landscape designers should seriously consider the use of permeable paving materials such as aggregates stabilized with Organic-Lock™ for their next project.

References

[1] Zeugel, D. (2018). We Should Be Building Cities for People, Not Cars. Strong Towns. https://www.strongtowns.org/journal/2018/7/2/we-should-be-building-cities-for-people-not-cars

[2] [3] Jeffries, S. (2018). Pavements are for everybody. Except pedestrians. The Guardian. https://www.theguardian.com/commentisfree/2018/feb/27/pavements-pedestrians-cyclists-walkers-hire-bikes

[4] Meng, Y. (2019). Don’t forget the footpath – it’s vital public space. The Conversation. https://theconversation.com/dont-forget-the-footpath-its-vital-public-space-115151

[5] Sharpin, A., Welle, B., Luke, N. (2017). What Makes a Complete Street? A Brief Guide. The City Fix. https://thecityfix.com/blog/what-makes-a-complete-street-a-brief-guide-nikita-luke-anna-bray-sharpin-ben-welle/

[6] [7] McCann, B., Rynne, S. eds. (2016). Complete Streets: Best Policy and Implementation Practices, Chap 5. Smart Growth America. https://www.smartgrowthamerica.org/app/legacy/documents/cs/resources/cs-bestpractices-chapter5.pdf

[8] [9] [11] Chithra, S.V., Harindranathan, N., Amarnath, A., Anjana, N.S. (2015). Impacts of Impervious Surfaces on the Environment. International Journal of Engineering Science Invention, 4(5), pp. 27-31. http://www.ijesi.org/papers/Vol(4)5/E045027031.pdf

[10] Frazer L. (2005). Paving paradise: the peril of impervious surfaces. Environmental health perspectives, 113(7). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1257665/

[12] Thorpe, D., Zhuge, Y. (2010). Advantages and disadvantages in using permeable concrete as a pavement construction material. Association of Researchers in Construction Management. https://www.researchgate.net/publication/228482416_Advantages_and_disadvantages_in_using_permeable_concrete_as_a_pavement_construction_material

[13] Khoury, N., Zaman, M. (2007). Environmental Effects on Durability of Aggregates Stabilized with Cementitious Materials. Journal of Materials in Civil Engineering, 19(1). https://ascelibrary.org/doi/10.1061/%28ASCE%290899-1561%282007%2919%3A1%2841%29

[14] Abel, K. (2016). Trends in LEED Buildings and their Effects on Urban Permeability. GIS For Water Resources. Accessed: 24 Feb 2019. Available from: https://www.caee.utexas.edu/prof/maidment/giswr2016/Papers/Abel.pdf