Calculate the slope of a road

[GIS_USERGIS_USER]

Hi,

I need your help to calculate the slope of a road feature class.

My data are :
- an elevation surface
- a polyline feature class

My softwares are :
- ArcInfo 10
- Spatial Analyst

I just would like to know the best way to do this because I don't know well Spatial Analyst.

Thanks for your help/advice...

GIS_USERS

[GayathriAlallasundaram · Accepted solution]

Hi,

If you have 3D Analyst extension then you could use the Add Surface Information Tool (ArcToolbox > 3D Analyst Tools > Functional surface)
The Add Surface Information Tool will add Min/Max/Avg slope to a line.

If you do not have 3D Analyst extension but only Spatial Analyst extension then use your DEM create a slope using the Slope tool (ArcToolbox > Spatial Analyst tools > Surface). Then convert your polyline to points. Use Extract Values To Points(ArcToolbox > Spatial Analyst tools > Extraction) on the Slope Raster. This will give the Slope values for these points and then you could perform a join between points and the polyline.

-Gayu