AutoCAD Civil 3D General Discussion

AutoCAD Civil 3D General Discussion

Message 11 of 18 (364 Views)

Re: Speed humps

04-06-2010 03:55 PM in reply to: CRThorn

Agreed. The grading object is the easiest for a ramp-flat-ramp shape.

Depending on the proposed uses of a fully detailed model, I'm not sure
that I would bother adding the hump to the model.
For construction purposes a detail (as others here have noted) is all
you need.


Laurie Comerford

CRThorn wrote:
> Its a Ramp flat ramp.
> The grading idea is a good one I may try that. I dislike grading though and avoid them where ever possible!
> Thanks
Valued Contributor
Posts: 73
Registered: ‎09-04-2008
Message 12 of 18 (364 Views)

Re: Speed humps

04-07-2010 01:06 AM in reply to: CRThorn
Thanks for the advice, I have never really thought about the issue of over modeling. I'm a bot or a perfectionist when it comes to civils and model most of the detail in.

In this case I will use a label to "fake" the height at the top.

As for the planning in this case the speed humps were a requirement of the client along with narrowing as they are trying to keep the speed down to 15mph. I do see what your saying though, speed humps have no place on minor or major traffic routes.
*John Mayo
Message 13 of 18 (364 Views)

Re: Speed humps

04-07-2010 06:26 AM in reply to: CRThorn
All excellent points Laurie but just when you don't want the humor, along
comes a flying motorcycle...


John Mayo, PE

C3D 2010, RD 2010
Core i7 920 6GB DDR3
Radeon 4870HD 1 GB
*Laurie Comerford
Message 14 of 18 (364 Views)

Re: Speed humps

04-07-2010 06:50 AM in reply to: CRThorn
Hi John,

Again factual. I ommitted flying cars although there are reports of
that happening as well.

On 7/04/2010 11:26 PM, John Mayo wrote:
> All excellent points Laurie but just when you don't want the humor, along
> comes a flying motorcycle...
> :smileyhappy:



Laurie Comerford
Distinguished Contributor
Posts: 228
Registered: ‎04-10-2008
Message 15 of 18 (364 Views)

Re: Speed humps

04-07-2010 05:32 PM in reply to: CRThorn
I do terrain modeling in C3D for machine control. I also do 3d renderings for presentations. For machine control, I model subgrade. That's what our machines grade to. A finish grade model for machines is too much trouble. I build very complex and detailed models since that guides our machines, but I would never need speed humps in a model for machine control. I don't think I would take the time to do it for a presentation model either. I may put a yellow stripe across the road in their locations. It's just way more trouble than it's worth in my opinion.
Distinguished Mentor
Posts: 823
Registered: ‎11-15-2005
Message 16 of 18 (364 Views)

Re: Speed humps

04-07-2010 09:05 PM in reply to: CRThorn
I was a dyed-in-the-wool hater of speed humps. Then a drunk teenager in our neighborhood got into his daddy's Corvette and did a Daytona 500 around our 'hood. He lost control, flew into a parked RV with an elderly couple sleeping inside, and killed them both instantly. The city installed speed humps within a month and now traffic flows at no more than 25 mph. The humps cause a minor but acceptable vertical acceleration, they eliminate speeding in what was otherwise a wide, straight street at moderate slope which enticed speeds of 35 to 40, and everybody in the neighborhood is very happy with them. If nothing else, they force "outlanders" to seek another route, which is fine by us.
So, what are the other choices? Design very narrow streets with lots of parking, very curvy streets where higher speeds are not likely, or some kind of speed modifications like humps or chicanes or the like. Personally, the humps are my preference in residential settings. Properly designed, one can drive them easily at 25 mph, ande spaced properly, no one accerlerates between them, and they have gaps in between to allow emergency vehilces to, essentially, avoid the interuption. As for flying motorcycles... drive safe like the rest of us.
Distinguished Contributor
Posts: 232
Registered: ‎07-07-2006
Message 17 of 18 (363 Views)

Re: Speed humps

04-12-2010 09:58 AM in reply to: CRThorn
For our more detailed work which requires technical approval by the local authorities prior to construction, we now have to show speed tables on the carriageway profiles and on the contour plans. I've previously had a number of councils complain that our plans didn't show the 'real world' road surface on the plans or where they are on the longitudinal sections.

Furthermore, the local design standards for some authorities specifically require us to put in speed tables, tabled junctions etc as opposed to more bends etc.. In fact, some layout architects use speed humps as a way of manipulating the highways layout to increase the developable area.

We're based in England so things may be different elsewhere with less bureaucracy!

The way we do all this is by using raised sub-assemblies first then when the highways are technically approved, manually inserting 3D polylines representing the table/ramp edges if we need more detail (it's much quicker).
Valued Contributor
Posts: 73
Registered: ‎09-04-2008
Message 18 of 18 (363 Views)

Re: Speed humps

04-13-2010 01:20 AM in reply to: CRThorn
I'm in that same situation.

This is the solution I have used and I think it works well.

1. Do you longsection and corridor design as normal.

2. Then go to the profile and create a new profile called ramp or whatever suits.

3. Draw the ramps onto the longsection.

4. Create a new corridor with a road only assembly.

5. Now split it into regions for ramps and non ramps

6. Set a new blank assembly up called none (just the marker)

7. Set the blank assembly to any part of the road without a ramp.

8. Now create a new surface called finished, final, etc...

9. Paste the main corridor surface first then paste the ramp surface (You will have to manualy delete the stray triangles in the ramp surface, takes no time at all)

10. Turn you main and ramp profiles off through the style and add the finished surface to the longsection.

This may look long winded but once you have done is once or twice it will be quick. It took me 15mins to design 4 ramps which also included narrowings. This also means the ramps will follow any superelevations you may have if you near a corner or change in chamber/crossfall.

If this needs clarifying just ask

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