Trees and bike paths still sometimes obstruct each other. Root pressure can turn an even surface into a bumpy bike path full of cracks. Repairing cracks is an annual expense. To solve this, one often considers the impact trees have on the bike path. Easypath has turned this issue around and has Tree Watch Netherlands approached to conduct a survey with the question: "What impact can a bike lane have on tree development?". From this study came a surprising conclusion.
Trees play a major role in addressing the climate problem, contributing to clean air and a healthy living environment. In urban areas where space is limited, it is not a given that trees are given space. "An urban tree lives to 40 years on average, says tree specialist Ronald van den Brink of the Netherlands Tree Watch. "And that's way too short, because a tree doesn't really start delivering its benefits until after those 40 years." Due to the petrification of many inner cities, there is limited space for trees. Even when the tree does get a place in a design, the growing space is often too small. "When it comes to climate adaptation, we want to preserve those trees as much as possible," he said. saidJim Brewer, commercial director at Easypath®. Brouwer wanted to test whether the concrete elements, used to lay the bike lanes, impede the development opportunities for trees. He asked the Bomenwacht Nederland to investigate this.
Bomenwacht Nederland surveyed bike paths in four municipalities and was asked three questions:
The Tree Watch went to work in 2021 and chose two existing bike paths with paired concrete slabs: one laid in Wageningen in 2006 and one in Teylingen, from 2013. In addition, a traditionally constructed bike path in Haarlem was examined. The researchers also visited a site in Amstelveen where they wanted to replace a traditional bike path with the construction with coupled concrete elements. The researchers conducted a growth site study, assessing a number of trees and examining the soil immediately adjacent to and under the bike lanes. "How do the bike lanes look now with the trees along them, is there a problem with roots, do those roots go underneath, how thick are those roots, what is the quality of the growing place, etcetera", Van den Brink explained. "And how does that differ with concrete elements and asphalt or tiles." In addition, Bomenwacht asked municipalities to complete a questionnaire.
Easypath® paired concrete elements came out positively from this study, both for bike lanes and trees. Van den Brink explains why. "It is the combination of less compaction and extra space. With traditional bike paths, the subgrade is heavily compacted and allows less water and oxygen to pass through. The roots seek higher ground and then grow through the foundation layer. With linked concrete elements, that foundation is barely compacted, because pressure distribution is greater and compaction is less necessary, giving water and oxygen space." The Tree Watch found that beneath the concrete structure was ample oxygen for the trees. If tree sand is applied, conditions for the trees will be further improved. Because the soil is not compacted and sufficient oxygen and water are present, roots can grow downward when concrete elements are applied. Where there is enough room to continue growing. This offers a great advantage in cities. This almost doubles the growing space under the concrete slabs and extends the life of the tree. "The greater the rootable space, the larger a tree can grow and the longer it will last," he said. says Van den Brink.
Brewer was surprised by the outcome. "That we offer an integral solution that prevents root and push-up damage, we knew. This is obviously a nice confirmation. But we are especially pleased that with our application we can provide an optimal growing place for trees, both in new and existing situations. Because our concrete elements are modularly laid, it is possible to remove these elements to optimize the growing site or add tree sand. And this is important as we face drought and heat stress."