Pathfinding problem - underground service road

[MattB5G]

I built an underground service road connected to my medium stands on the inside of my terminal (see screenshot). It has a down ramp near the service vehicle depot and an up ramp near the medium stands. However, vehicles cannot seem to get to the medium stands. They go around in circles, go over by the small stands and do U-turns (see the blue pushback truck in the screenshot as an example), and even when they do go down the down ramp they immediately turn around and go back. Anyone know what may be causing this or what I'm doing wrong?

https://steamcommunity.com/sharedfiles/filedetails/?id=1860019788

[Llogeyr]

One of your tunnel ends are most likely the cause. I had this problem as well. Even though I used a down tunnel and an up tunnel I had to set 2 up tunnels. Or vice versa. Forget which one.

[MattB5G]

Thanks. I’ll give that a try. I’d also suggest for the future that there shouldn’t be “up” and “down” tunnels, just a “surface to tunnel” connection.

[Tryshard]

My experience has been that the down ramp works properly. The up ramp needs to be installed backwards. When you do this it works.