No antivirus, and I ran it as administrator. I ended up installing v14 from a mirror I found here, and that seems to be working ok. Thanks anyway 
Am I missing much by using 14 instead of 15 or 16?
I wasn't able to find specific release notes.

Am I missing much by using 14 instead of 15 or 16?
I wasn't able to find specific release notes.

My main concern was handling multiple roads. I've seen lots of pseudo3d roads online, but not many implementations of road splits. I tried several options, but settled on the one I will show below. While it has some limitations, I think clever map design will hide most of them 