Cities Skylines: Slope too steep?

Your new interchange

Interchange

Here it is. Compact, efficient, useful. You'll use this all over your city. Right?

Wrong.

Slope too steep!

It doesn't even place. "Slope too steep"? The ground's perfectly flat!

Well, sort of. Go to ground level and you'll see that most areas gently slope. But that shouldn't be a problem for any decent interchange, so what's the cause?

The culprit

Very steep ramp

No, not the street lamp, it's the ramp. It's too steep. It works fine here, but given even gentle terrain it'll fail to place.

Chances are, you've done this...

Shortest slope possible

It's tempting to build the shortest slope the game will allow. After all, you're cheap and everyone likes a bit of excitement in their morning commute.

But when it adjusts to the terrain, it'll be made even shorter, and the game won't like that at all.

...and this is what you should do

More room

Just give it a little bit of breathing room. 1 or 2 extra steps is fine.

Look at the difference!

Ramp comparison

Coincidentally, this is where we separate the men from the boys.

Your new interchange!

New interchange

You'll use this all over your city... you hope.

It works!

No error

The cougars will be thrilled with their shiny new interchange.