I remember when they put the central reservations in on the main roads in Calis. The middle was filled with soil and was wide enough to plant palm trees in easily. Sadly, nobody had thought about the roots - the fact that they were about twice as wide as the trunk and two kerbstones on each side, every 10 metres or so had to be cut out and removed, the trees put in and the kerbstones returned into place. You couldn't make it up.