topic Re: I have a polyline feature representing a road casing. Can anyone offer some guidance on how to convert this polyline into a single polygon? help appreciated. in Mapping Questions

I have a polyline feature representing a road casing. Can anyone offer some guidance on how to convert this polyline into a single polygon? help appreciated.

RobertWilliams3 — Fri, 06 Jan 2017 16:37:55 GMT

Hi, i'm trying to achieve a polygon layer that represents the roads in my study area. I have my road data, which is multiple polylines making up the road casing. I'm struggling to find a way to convert these polylines into a single polygon of the road network. Any help much appreciated,

Thanks

Re: I have a polyline feature representing a road casing. Can anyone offer some guidance on how to convert this polyline into a single polygon? help appreciated.

ChrisDonohue__GISP — Fri, 06 Jan 2017 16:59:29 GMT

There are several ways to convert lines to polygons. How it can be done varies by software/licensing:

What version of the software to do have? What license level?

Also, what have you tried?

One option is to use the Feature to Polygon (Data Management) geoprocessing tool. However, this requires an Advanced license level.

ArcGIS Help 10.1

One guess on what you are running into - I suspect one complication may be that the cased lines result in an "open ended" form, so some of the polygon creation methods fail as they don't know how to span the gaps.

Chris Donohue, GISP

Re: I have a polyline feature representing a road casing. Can anyone offer some guidance on how to convert this polyline into a single polygon? help appreciated.

DanPatterson_Retired — Fri, 06 Jan 2017 18:50:03 GMT

again with the advanced.. Collapse Dual Lines To Centerline—Help | ArcGIS Desktop and

Collapse Road Detail—Help | ArcGIS Desktop then if you really need polygons, buffering would be simpler and faster if most of your rroads are standard width... otherwise you have to close of polylines to form polygons or buffer by differing widths depending on road type.

Re: I have a polyline feature representing a road casing. Can anyone offer some guidance on how to convert this polyline into a single polygon? help appreciated.

AdrianWelsh — Fri, 06 Jan 2017 18:53:00 GMT

Robert,

How do you have the original data? Is this in a GIS format or a CAD format?

Re: I have a polyline feature representing a road casing. Can anyone offer some guidance on how to convert this polyline into a single polygon? help appreciated.

AbdullahAnter — Fri, 06 Jan 2017 19:48:51 GMT

I think the best way to convert roads feature to polygon feature is Using Buffer tool.

Buffer.

then to make single polygon for each road use Eliminate tool for the output layer from buffer .

eliminate

Re: I have a polyline feature representing a road casing. Can anyone offer some guidance on how to convert this polyline into a single polygon? help appreciated.

RobertWilliams3 — Fri, 06 Jan 2017 21:36:35 GMT

Many thanks for the replies, much appreciated. The data is from Ordnance Survey local vector data. I tried the feature to line method but all I achieve is a few polygons created inbetween the road network, rather than filling the casing itself. I had thought about the buffer method as I have road center line data too. Thanks again, i'll see if I have any joy.

Re: I have a polyline feature representing a road casing. Can anyone offer some guidance on how to convert this polyline into a single polygon? help appreciated.

RobertWilliams3 — Sun, 08 Jan 2017 16:36:50 GMT

Thanks for your reply Dan. The buffer method worked. I now have polygons representing the roads. I have however encountered another hurdle. I now want to incorporate/overlay these road polygons into a layer of habitat types so that they replace the polygon underneath (effectively becoming a habitat category itself). Any ideas on how to achieve this would be most welcome? thanks

Re: I have a polyline feature representing a road casing. Can anyone offer some guidance on how to convert this polyline into a single polygon? help appreciated.

DanPatterson_Retired — Sun, 08 Jan 2017 17:33:08 GMT

Yes... there are several tools in ... An overview of the Overlay toolset—Help | ArcGIS Desktop like intersect and union... the choice really depends on what you want to happen to the geometry and what you want to happen to the tabular output. I would advise a slow read through the materials to familiarize yourself with the tool functionality

Re: I have a polyline feature representing a road casing. Can anyone offer some guidance on how to convert this polyline into a single polygon? help appreciated.

RobertWilliams3 — Sun, 08 Jan 2017 20:51:43 GMT

Great! the 'Itentity' tool worked. Thanks very much Dan.