Cannot Build Roads on Site-Graded Terrain

[Vectorus]

I build a biodome on a gas giant core, where the terrain is uneven and curvature high. Now, although the area inside the biodome is graded flat, I cannot build any roads on it, since, in many areas, the start and end points are too high or too low compared to the "virgin terrain".

In some cases, it then becomes impossible to connect buildings within or between biodomes without creating useless filler buildings just to get them in range of each other.

I submit that roads should consider compare their start and end heights to the existing height of the graded or site-graded terrain, not the virgin terrain. I realise that this will allow strange things to be done, but these strange things are less harmful to smooth and enjoyable gameplay than the frustration of not being able to place roads at all.

[Greydog]

I usually set the grade of the dome by placing the arrowed entrance with a road slightly entering it. Where the arrow starts with the 'dot' is where the dome will be graded at. Unless something has broken recently you should be able to link the rest of your roads to it.

[Vectorus]

I need to play around a bit more to find out the exact situation where this problem appears. After relogging today, I found that a graded biodome yesterday now supported roads built within its graded area. Yesterday, they were rejected as being too far away from the virgin terrain level. (Is "virginity" recalculated at some point after buildings alter a planet's shape?)