Drawing a proposed cycle-way

Here is my proposal for a bike cycle-way design.

On my various rides I have thought about various features a good design might have:

1. It must be as flat as possible, or going slightly down-hill if at all possible.

2. It must keep off the rain and sun, yet still offer the riders a view of some sort,as well as ventilation.

3. The route should be as direct as possible.

4. There should be enough width for 3 cyclists coming and 3 going. The reasoning behind this is that if you are cycling with a friend, you will need 2 spaces, and that leaves one space for quicker passing cyclists.

5. There should be a barrier, about 800mm high between the opposing flows of traffic.

6. If possible, it should look modern and elegant.

The upshot of all of the above, is a cycle-way that is about 6.3m wide, if weallow for 3m each side and say 100mm for walls and barrier.
One thing is that these would be made in a factory and it is probable the length would be limited to how much length the roads can take.I have guessed at 32m.

Other aspects of my design could be criticised:

1. 6.3m wide is quite wide: could this be cut back by having the other opposing traffic in its own span?

2. There is a privacy issue for people living beneath one of these things-It is possible there could be screens over the window openings.

3. Every 32m there would have to be a very solid tower to hold it all up. This tower would have to be capable of having a truck run into it, if it is anywhere near a road...which is likely.

All we need now is a concrete designer to work out the loadings!

Re Autocad R2010:after my last post, I checked out RobiNZ cad blog (see the link in the links part) and had a look at the official web launch demo. I think the 3D free form modelling seems to have a lot of good things going for it, and the demo shows off the parametrics quite well.