AutoCAD Civil 3D

[#1]

We have lucky enough to obtain LIDAR for most of our small City as well as ground only points.  My problem is that profiles produced using it are rough and jagged (see attached).  I've tried contour smoothing to no avail as well as point removal.  Perhaps I haven't just tried enough options.

Should mention also I have breaklines along the CL alignment as well as Edge of Pavement.

Any ideas?

[#2]

With Lidar you're pretty much stuck.  There's really too much data and without proper breaklines it doesn't triangulate along the road crown as it should.  We have had some success at creating a "fake" ground profile by drawing a featureline to trace the centerline where it's visible in the photo.  You can either snap the featureline points to the Lidar nodes or use the Elevations from Surface command, then project the featureline onto your profile view.

[#3]

Judging the contours in the plan view it appears the LIDAR surface has issues. The contours in the paved areas should not be meandering like that. I'd run some checks on the surface and source data.

Do you receive breakline data with the LIDAR dataset?

[#4]

No we didn't but I have 2d polylines as breaklines in the drawing at the edge of pavement and the centerline.

[#5]

Like Steve, I would look at using the lidar data to recreate the Roadway. Either with FL's or a layout profile and simple corridor to extract the FL's for CL and EOP.

[#6 · Accepted solution]

What would a normal preliminary survey be in your area? We usually see surveys with a cross section every 25m and for each feature of the road. At the most this is what I'd have to define my EG in this instance. Clearly the LIDAR data is overkill for road design. 

Maybe you could try to insert a point along each of the breaklines at common interval and redefine your EG surface to be something like EG_reduced. Good Luck.

[#7]

Thanks to all that replied, for now I think the idea of placing a point on the Lidar Surface every 25m would be a great idea combined with a 3D poly breakline.

I have always had problems with jagged profiles and a 3D poly breakline has always solved them.