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Speed humps

17 REPLIES 17
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Message 1 of 18
CRThorn
3303 Views, 17 Replies

Speed humps

Hi,

Does anyone have a smart way of designing in Speed humps to a residential road with kerbs?

I have a few ideas all of which a a pain:

1. create a new sub-assembly which has the road level raised to the max level of the hump. Then use the custom frequency to mark the bottom of the ramp and it should work out the rest.

2. Create a 2nd profile on the longsection in the place of the speed hump then add an addtional corridor in each location over the top of the normal. I would then use the paste surface command to create the final contour plan.

As you can tell these are not very elegant. Any other ideas?

Chris
17 REPLIES 17
Message 2 of 18
Anonymous
in reply to: CRThorn

Hi Chris,

What longitudinal shape do these "highly visible admissions of planning
failure" have?

Are they "ramp-flat-ramp", or "Watts profile" or some other?

One simple approach is to complete the design without them, then create
a grading object of the hump and paste it to the road design surface model.


Regards,


Laurie Comerford

CRThorn wrote:
> Hi,
>
> Does anyone have a smart way of designing in Speed humps to a residential road with kerbs?
>
> I have a few ideas all of which a a pain:
>
> 1. create a new sub-assembly which has the road level raised to the max level of the hump. Then use the custom frequency to mark the bottom of the ramp and it should work out the rest.
>
> 2. Create a 2nd profile on the longsection in the place of the speed hump then add an addtional corridor in each location over the top of the normal. I would then use the paste surface command to create the final contour plan.
>
> As you can tell these are not very elegant. Any other ideas?
>
> Chris
>
Message 3 of 18
CRThorn
in reply to: CRThorn

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
Message 4 of 18
Anonymous
in reply to: CRThorn

...What longitudinal shape do these "highly visible admissions of
planning
failure" have?...

That is hysterical Laurie

Joe
Message 5 of 18
Anonymous
in reply to: CRThorn

I wouldn't model this unless this high level of detail was needed in section
or profile.

The change in the contour is minimal. I would probably use an expression in
a surface label to raise the grade to height of the speed bump & just throw
some labels on the plan at the speed bump location.

If the design changes, you will need to edit the speed bumps. If you use
gradings & need to explode them (I believe this is still the recommend best
practice for stability), they will need to be rebuilt.

If you simply label the speed bumps & the design changes, the speed bumps
need no additional revision time.

--
John Mayo, PE

C3D 2010, RD 2010
Core i7 920 6GB DDR3
Radeon 4870HD 1 GB
Vista64
Message 6 of 18
awood
in reply to: CRThorn

Agreed Joe - LOL

Cheers,

AWood
Message 7 of 18
apweng
in reply to: CRThorn

Why model a speed bump when this is likely an engineering detail?

Over-modeling, in my opinion, is the source of many of the problems/challenges associated with "model based design technology" (not BIM by the they way, which I know is going to open a can of worms).

If you're needing to create a 3D model for visualization/analysis fair enough, but you really need to think about how your design information is going to be used. Many contractors construct from hard copy plan/profile drawings. Many also use design points that are uploaded to survey total station / GPS equipment for field surveyors. Machine controlled grading is sometimes used in larger projects.

I continuously run into designs where enormous amounts of effort have been put into trying to create the perfect model, when in actuality, most of that detailed information is never used. It may look pretty, but not very useful from a practical scenario.

Having said that every situation is different and it really helps to know what you're delivering as part of the design process, and how that information is going to be used.

Andrew
Message 8 of 18
Anonymous
in reply to: CRThorn

Excellent points Andrew.

An advantage of a dynamic model should also be the ability to revise it
fast.

--
John Mayo, PE

C3D 2010, RD 2010
Core i7 920 6GB DDR3
Radeon 4870HD 1 GB
Vista64
Message 9 of 18
Anonymous
in reply to: CRThorn

...and let me add I have learned this the hard way.

--
John Mayo, PE

C3D 2010, RD 2010
Core i7 920 6GB DDR3
Radeon 4870HD 1 GB
Vista64
Message 10 of 18
Anonymous
in reply to: CRThorn

Hi,

For once I was not trying to hilarious. If you have a design where you
need speed humps to make it functional, then the design IS a result of
planning failure and the speed humps are the visible admittance of that
fact.

It amazes me here where I see roads that for various reasons have gone
out of shape and Authorities spend a fortune re-building them to make
them smooth and finally tack on speed humps to make them rough again.

Speed humps also ensure:

an increase in wear and tear on the vehicles using the road,
increases of noise levels as drivers accelerate back to operating speed
the occasional flying motor cycle
increased construction costs
increased driver resentment

If they must be used and there is enormous political pressure to use
them in many circumstances, then, although harder to build, the Watts
profile is by far the best shape to use.

Regards,


Laurie Comerford

AWood wrote:
> Agreed Joe - LOL
>
> Cheers,
>
> AWood
>
Message 11 of 18
Anonymous
in reply to: CRThorn

Hi,

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.


Regards,


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
>
Message 12 of 18
CRThorn
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.
Message 13 of 18
Anonymous
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
Vista64
Message 14 of 18
Anonymous
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...
>
> 🙂
>

--

Regards

Laurie Comerford
Message 15 of 18
keithknifer
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.
Message 16 of 18
castled071049
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.
Message 17 of 18
ksorsby
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).
Message 18 of 18
CRThorn
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

Chris

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