Generating different density road networks for subdivisions of a polygon extent

MelanieVT

Hi all,

I have a land-use polygon file containing four different land-use types, as shown below.

land-use map

I have learned that I can introduce an obstacle map to exclude no-road network areas. So, no problem with the recreation polygon. However, I’m having trouble generating three different-density continuous road networks inside three residential areas. I mean, I can generate different-density road networks separately using different parameters. In this case, they are unconnected. So, is there a way to cope with this problem?  For example, is it somehow possible to introduce the land-use file containing different segments (as in the case of the obstacle map), define separate parameters for each, and generate an integrated network with different densities?

Cheers,

Mel

ThomasFuchs

Hello @MelanieVT 
Thank you for the question. I suggest taking an iterative approach using multiple obstacle layers: 
Obstacle layer—ArcGIS CityEngine Resources | Documentation.

1. Create an obstacle layer for the high-density residential area and grow a dense street network
   
2. Then grow a separate, more sparse network for the medium-density residential area as an obstacle.
   
3. Proceed with the low-density residential area accordingly 
   
4. Now combine all three networks in a single layer and do a graph cleanup: 
   Cleanup streets—ArcGIS CityEngine Resources | Documentation
   
5. To ensure all parts are connected, grow the network together using the recreation area as an obstacle layer.
   
6. Finally, create a continuous road network by analyzing the graph and adjusting the street widths
   Analyze graph—ArcGIS CityEngine Resources | Documentation