On 11/01/2017 14:57, NY wrote:

Roundabouts are great until the road planners make one of three silly
design decisions:

- Placing high barriers, hedges or signs on the central reservation as
you approach the roundabout, so you lose sight of traffic coming from
your right at the critical time when you need to see it, only regaining
sight of it again when you are virtually at the give way line.

Though you think it's a bad idea, actually it's a sensible response to
people thinking they can see enough and hence approaching the roundabout
too fast, then crashing. If you can't see, you have to slow down. If
people didn't overestimate their abilities coming into roundabouts, this
wouldn't be necessary, but they do so it is.

- Placing new roundabouts off-axis of the major road so traffic on the
road with greatest flow has to deviate from the straight ahead route
that it used to take before the roundabout was there.
https://goo.gl/maps/yVwWuTRgU4R2 is an example: this shows the road
before a new roundabout was put in.
https://s29.postimg.org/j24hmuymf/edencamp.jpg shows the new roundabout
(in red) and a new road to serve a large development near there. The
green circle shows where (IMHO) the roundabout ought to be. There seems
to be a tendency with modern roundabouts to direct traffic towards the
centre of the roundabout, with a tight left-curve in the last few feet,
instead of splaying the entry and exit lanes slightly to direct traffic
tangentially towards the outside of the central disc.

Same game - it's about slowing you down.

- Placing *raised* mini-roundabouts at junctions which used to be T
junctions, such that traffic turning right has to make a very
exaggerated left turn first of all to get onto the roundabout and to
negotiate it without the rear wheels bumping over the hump. If there is
insufficient space, the roundabout should be a painted disc so traffic
can drive over the middle, once the roundabout has done its primary job
of establishing equal priority to all the roads that lead into it.

You are allowed to drive over the raised bit of a mini-roundabout -
that's why the edges are gentle, not kerbed. On the one near us, pretty
much everybody turning right does it, and it's fine.


They are infinitely better than American four-way-stop junctions which

Isn't almost anything better than those?