Picture is taken from the City Journal, Northwoods.
(https://lh3.googleusercontent.com/4U8ENIhxXouLOrHDybdRTWgF3c2lIZ1hzls1h132Cl6MB5j9YwrGmmY3eyGArpIYsk2sLe-1aJ8NABf6yf4ecUlkGCVKkU-NHhVNXZhKhUZv1WKFCJKz8uGtFT9H30PEnybAhlh2fW57ovSA037I9lieZ_8OUip43ebrPwSzZgdDFA8kBJsUJLDqRx3oQX5QnokzjAoqAI1QpYYSjvvA45wua_pcaD7AOFW_2afKJ_oylEDn2kFGLy6HUxRggWCpo37vJrAm2GlflB83z5U76k-T0v_eFSAzcBZy4f7-MpiR-5umQ7zfgHzde34kkVznBFU7uCn8bFSUdrr5zk058ydaDLTq0sboVwbqxCoFMfYEvFKRI9UJhcW81Wi6m2RyOwqGKkJHXSeVOgMBm0T6CBwlyJlMP-CmfbYP1Uyw4kx9asiFCn8H8oHfqkQWaN_y4l_ocYh47Gs9kJd_ifzEOP-H4BObZe0_Kl8DcnRAmPAFjhWRBcJOFQRvjJpLAoscS9rWbasGDElqAIGZFIibPFiQ30r97i9HhtywSDG_3Rl-err6PUue5ZiFhcsLkcTBbkNXs0McOCy4E52_2cSc9g8IIviGzblXt0N6la4wrOE_5YjW9V6HsFG7IwRbGC2pegENS0J8HwClF5xjItgKFcp6gwNl4WzHsNCYpc1PdZ0OCf0JE3TDOZJZnAzF=w800-h600-no?authuser=0)
I must be missing out on a new NAM as these diagonal roads/diagonal curved roads seem to be popping out in many places ()what().
They are currently still under development, and some people have had the opportunity to test them in pre-release. The next NAM should include these new pieces.
To extend on what Casper said, that would be the FAR/FARR development. You can see a lot of progress on it in the Three Rivers Region topic.
Here is an example post of some of the other things it can do:
http://sc4devotion.com/forums/index.php?topic=112.msg188201;topicseen#msg188201
That was interesting ::)