Now, I have since found the original tutorial here and it makes a lot more sense.
The problems I encountered were:
Flimsy - the newspaper rolls simply weren't sturdy enough. The tutorial says to use 2 sheets of newspaper (broadsheets I realised after I initially tried to use the Sun!). The original tutorial suggests 4 sheets and I would think that would work a lot better. You will need a lot though - I would imagine at least 6 copies of a large paper (I used the Independent which seemed a decent size but used 3 copies and still ran out.) Actually, when my newspaper ran out I used 2 sheets of brown paper which actually did seem sturdy enough for the project. This kind of defeats the point of a free recycled project though (but after an evenings' work and so near to finishing I just wanted to finish the thing!)
The ends were also particularly flimsy (obvious really although I didn't do anything about it at the time!). I would suggest either folding the corners in before you start or cropping them all to the same length.
No. of rolls
The Modern Parents Messy Kids tutorial I found says they did theirs with 25 rolls. Coping their design I found I needed at least 30 and could have done with around 10 more for added support. (again at an ideal of 4 sheets a roll this would be at least 120 sheets (4 page no's in a newspaper))
So if you plan to try I would look at both tutorials as there are good ideas in both. You will need:
6 - 8 Broadsheet newspapers
Tape and possibly also staples to fix triangles together.
Here's my photo diary of it all....
And it lasted about half an hour the next morning!! Saying that it was still played with all day as a road system!
And by the end of the day.....
I think I will probably try again - watch this space!