By Seth Kerr
As Nairobi works towards implementing its mass rapid transit system and boosting its non motorised transport infrastructure, additional options are available to move towards a more sustainable city. These options include recycling tyres for pedestrians, energy generating sidewalks, solar powered bicycles lanes, water absorbing concrete and energy generating roadways.
Tyres for Pedestrians
Cities across the United States like Santa Monica, Seattle and Washington D.C. are using recycled tyres, and even recycled plastic, to build rubberized sidewalks. The idea came to fruition primarily in order to save trees from the damaging affects of concrete sidewalks. Small sections of rubber sidewalk are used near trees in order to save both the tree and the sidewalk from damage. Recycled tyre based sidewalks have a number of other benefits too:
- Flexibility to move not only with tree roots but also with shifting soil
- Safety by providing softer, smoother surfaces for pedestrians
- Porous material which allows rain water to reach the soil beneath the sidewalk
- Low maintenance requirements and often times low maintenance costs
- Reduced impact on peoples’ joints
- Environmentally friendly alternative to landfills and/or burning of discarded tyres
Now is an excellent time for Kenyan officials to look into how discarded tyres could help Kenyans instead of harm them. Kenya, as a whole, faces a significant problem from discarded tyres. In a report published in 2014 by the German company GIZ ‘34,000 tons of tyres were burnt haphazardly, dumped, destroyed or re-used by methods that pollute air, soils and ground water in 2010’. It is likely that these numbers have only increased since 2010.
GIZ partnered with Bamburi Cement LTD and other businesses to form Waste Tyre Management Kenya. The main aim of the partnership is to implement a sustainable waste tyre management system and to help the Kenyan government adopt an updated waste tyre regulation. The report states that ‘The cement industry is expected to be the main user for waste tyres in Kenya’ but why can’t pedestrians benefit from the re-use of discarded tyres too by turning them into sidewalks?
Problems to Overcome:
- For rubber sidewalks to be successful in Kenya, there would obviously have to be a market for them. City governments would have to be interested in purchasing them for installation. To date, there is no record of any Kenyan city using rubber sidewalks. With city governments becoming increasingly more cognizant of the need to provide quality infrastructure to pedestrians, this hurdle could likely be overcome with the right marketing especially with pedestrian oriented projects like in Ruiru, Kenya.
- Kenyan companies would have to produce these rubber sidewalks. Globally, there are many companies like Terrecon, KBI Flexi-Pave and Rubberway who make and sell rubber sidewalk materials but to import these to Kenya would be cost-prohibitive. Kenya has a burgeoning formal recycling industry and Kenyan companies like Eco-Sandals and Eco-Post are already keen on ways to capitalize off of recycling. Why not add rubber sidewalks as one of many possible recycled-rubber or recycled-tyre product lines?
- The cost of rubber sidewalks is usually more expensive than brick or concrete sidewalks in the USA. This would likely be true in Kenya too. Many cities are investing in rubber sidewalks in small quantities because they are being marketed to have lower maintenance needs as well as to be more cost effective alternatives to traditional sidewalks. Evidence is showing that rubber sidewalks may not be as cost effective from a maintenance perspective in all cases.
- The main impetus for rubber sidewalks in the USA is the protection of trees. It is unclear how significant of a problem this is in Kenya especially outside of central business districts. Surely, the application of rubberized sidewalks can be up-scaled beyond just protecting trees especially in a larger scale effort to protect Kenya’s environment and people from improper tyre dumping and burning.
Electric Generating Sidewalks
The company Pavegen produces flooring material capable of generating electrical energy through the footsteps of pedestrians. The technology has been used in plazas, train stations, shopping centers, airports and a variety of other locations across the world, including a project in Lagos, Nigeria. The technology can also be used to gather data on pedestrian or consumer behavior. In Nairobi, where nearly 50% of citizens walk and electricity is not always consistent, this technology could be incredibly useful in areas with high volumes of foot traffic or even in making shopping centers like WestGate mall more sustainable.
Solar Powered Bicycle Lanes
The Dutch town of Krommenie opened a bicycle lane constructed out of solar panels in 2014. In 2015, after a year of existence, the results came back positive showing the bicycle lane produced more power than originally anticipated; enough to power three households for one year.
Being so close to the equator, Kenya receives significant amounts of sunshine. Clearly, this technology could find fruitful application here. The real hindrance for this technology is that the construction costs are very high. As Nairobi and other Kenyan cities start to expand their bicycle lanes, this technology’s initial construction cost could be outweighed by the long term power-savings.
Water Absorbing Concrete
Flooding is a serious nemesis to communities across Kenya. It causes significant amounts of damage, disruption, injuries and deaths every single rainy season. The company Tarmac, based in the UK, has developed a product that could significantly reduce the negative effects of storm water. The company’s product called Topmix Permeable Concrete can absorb 880 gallons of water (36,000 millimeters) every minute. This concept is relatively new and comes with some limitations. Applied with other well designed storm water management techniques, the system could help Kenyan communities combat the rainy season.
Solar Powered Roads
Kenya shows no signs of slowing down on adding more roads and expanding existing roads. Why not make these roads more than just a way to get from point A to point B? Some countries like France are making their roads more sustainable and productive by turning them into solar panels to collect energy. France has an ambitious plan to install 1,100 kilometers of solar paneled roadways during the next five years with hopes of generating significant electrical power.
The company behind the technology, Colas, states that one kilometer of solar powered road is enough to power public city lighting for a city of 5,000 people. Again, with Kenya’s frequent sunshine, this technology could make a dent in Kenya’s growing power requirements. Construction costs are high with this technology too but over a number of years the power-savings could justify the business case.
Rubber sidewalks and other emerging technologies will not be a panacea for Kenya in creating more sustainable, equitable and safe cities. The difficulties in marketing, manufacturing and pricing of these different options may mean none of these technologies ever finds a home in Kenya.
Public awareness and research into these different technologies, however, could have a number of benefits:
1.) Business opportunities for Kenyan companies, investors and entrepreneurs
2.) Providing additional electricity
3.) Reducing the negative effects of flooding
4.) Improving non motorised transport infrastructure
5.) Protecting the environment and air quality
6.) Improving peoples’ health
Even if these technologies are implemented in Kenya, there is no substitute for applying the smart urban planning principles that make cities successful. It is true that Nairobi, and African cities as a whole, face unique challenges like informal settlements that require solutions designed and implemented by the local populace. However, many of the smart urban planning principles such as limiting sprawl and providing a number of quality transportation options fit Nairobi’s needs regardless of their western planning origins; these sustainable technology ideas could fit too.
Kenya has the opportunity to be a leader on the African continent; an opportunity to make Nairobi the example other cities strive to replicate. These technologies, and infrastructure as a whole, could help Kenya become a paragon of sustainability if the politicians, engineers and urban planners are willing to challenge the status quo and demand more for the health and vitality of cities and the people who inhabit them.