One thing I discovered yesterday is that you can reverse the direction of a one way road if you set the road tool to upgrade and then right click on the one way street you want to change the direction of (you have to have the one way street selected as well). No more uneven highways for me!
Maybe there's already a good way to do this, but I feel like 75% of my traffic problems could be solved if I had a quick, effective way to split a 2 way road into 2 parallel 1 way roads in a way that wouldn't allow for U-turns to mess everything up. A simple Y-junction that keeps the left and right sides completely separate is all it would take.
I'd been playing for a long time on 1 square, wondering how people were able to afford expansions so early. Only yesterday did I realize that the price for additional plots of land had cents displayed. So I thought I needed $3,600,000 when I really only needed $3,600.00.