Green Canopies and Roadways A noticeable trend over recent years in many countries, has been the interest in placing trees in immediate proximity to road pavements. More specifically, a number of design teams are working with engineers to beautify key roadways using trees in the central median.

The excerpt below from a recently published research paper supports that trend. Australian expert, Dr Martin Ely (University of Adelaide) recently undertook a quantitative study to obtain a ‘snapshot’ of the attitudes and practices of local government street tree practitioners and managers throughout Australia.

Streetscape design

Appropriate streetscape design is seen as a key starting point to successful street tree planting and establishment. Respondents were asked if they currently practice, or intend to practice, a range of streetscape design practices. The intent of the question was to obtain a ‘snapshot’ of respondent’s uptake of a number of streetscape design practices identified in the literature review, with provision for additional open ended comments. Figure 16 presents the percentage of respondents reporting that they do undertake certain practices.

Green Canopies and Roadways


Median planting was the most common practice, with most Council’s undertaking it in some form. This was followed by attempts to create more space for trees including larger planting sites, cluster planting and footpath widening. The least adopted practice was (costly) service relocation.

 Open ended responses (30 responses)

Resistance to innovative practices, by engineers and others was mentioned. More stringent constraints on tree planting in medians planting was raised, as was the option in some situation of ‘no trees’. Space available for tree planting was seen to vary between localities. Resistance to planting trees in the parking lanes was also noted. Other streetscape design initiatives raised included aerial bundled cable and WSUD installations with street trees.


The literature review identified a number of strategies for the design of streets to better accommodate trees (Urban 2007). The survey showed that a number of these practices have already been adopted by some Councils, primarily increasing space for trees through measures such as footpath widening. Other desirable practices such as service relocations are less widely adopted, primarily due to cost factors.

Click here 
to view the full paper.


Green Canopies and Roadways

Structural soil cells perform to National Road Standards while enabling bio filtration or vegetative growth.

Share with us your thoughts and experiences in utilizing median strips and areas adjacent to roadways for WSUD.