We had a question on the Facebook DIY Streets Turnpike Lane group page concerning the trees that are currently being planted on the raised tables. I provided an explanation on the group page, but thought I would also make it available on here:
We have chosen a ‘permeable’ tree guard which will allow for visibility. The species of tree (i.e. rowen) was recommended by the council tree officer as suitable for street planting since it does not have a large spread – certainly when pla…nted in a tree pit and maintained by the highway authority as part of their ongoing management of the highway.
Traditionally (1960s onwards), it was felt that junctions should have very generous junction radii and extensive visibility, but what tends to happen is that this encourages greater speeds as people don’t need to slow down to take a corner. In more recent, and celebrated, developments (e.g. Poundbury in Dorset) they deliberately create very tight junctions with buildings obscuring visibility onto the joining road – the result, people drive slowly and with care into and out of the junction. A controlled level of ambiguity can be an advantage in slowing traffic. The inclusion of trees within the carriageway can add to this controlled ambiguity in addition to their other multiple benefits, not least the softening of the streetscape. The fact that drivers will be slowed by the raised table at these locations will make it safer still since sight stopping distances are reduced at slower speeds.
We will continue to closely monitor all features, post construction, to ensure that they are working as anticipated and safe.