The game doesn't really handle bidirectional lanes well.

Two things you can try to discourage needless use: use per-lane speed limits to lower the lane's speed (I think there's likely room for improvement with regards to pathfinding and lane selection functions as I've seen vehicles putter along happily before). Second is to use lane arrows and connectors to force vehicles out of the lane at nodes and intersections (again, not sure how aforementioned functions handle such things).

You can use the lane connection tool in TM:PE on the nearest node to forbid oncoming traffic from using it, or at the intersection to keep cars from turning into it. I use that suicide lane road all the time for a dedicated left turn and I use the lane connection on all of them.

@smitty420 this kind of dampers the purpose of the even using the road. i want cars to use them like in real life. get in when needed to turn left in a the middle of a segment, not just at intersection nodes.