Road¶
Use this dialog to describe the road body.
Where do I find the dialog?¶
On the toolbox, select the SFI Properties... icon and then the Road tab.
Using the Dialog¶
The road body can be described using four different methods:
- Parametric
- Manual
- 3D lines
- Manual/3D lines
Road Parameters – Parametric Method¶
The road body is described with parameters:
Each surface in the road has its own road parameter
Info
Existing cross-sections are deleted before the profile generator creates new profiles. The layers in the road body are automatically rebuilt after road parameters are changed.
The parametric calculation method is typically used for designing simple roads and intersections. This is described in more detail in the general help under the section on design.
Road Parameters – Manual Method¶
The road body is described with the following surface tables:
- Surface Descriptions
- Side area (Rock Ledge, Minimum Ditch Depth, Earthwork Grading)
- Substructure (Deep Blasting, Removal of Topsoil and Vegetation, Soil Replacement, Riprap Layer)
- Extended superstructure: Superstructure, VIPS Special Grading Simple superstructure: Superstructure, Rock and Excavation Slope, Special Grading
- Closed Ditch
Road body described with surface tables
Note
Road parameters are not used, but surface tables as in VIPS. This is the description you get when importing a VIPS project.
The standard mode for this method is manual (hence the name manual method).
In manual mode, the profile generator retains existing cross-section data. This means that existing cross-section data that is not regenerated remains unchanged. Furthermore, the road body must be rebuilt manually using the Build Surfaces function each time a change is made in one of the tables.
Info
The manual method in manual mode is typically used for mass tracking and documentation of road projects. These are projects with gradual progress where you need full manual control in the cross-sections. This method is described in more detail in the general help under the section on execution.
The manual method can also be set to automatic mode. This option is relevant if you are designing with the manual method. Then, profile generation and building will occur as with the parametric method.
Road Parameters – 3D Lines¶
The road body is described with 3D lines.
The red points come from 3D lines
Info
The 3D line method was introduced to support tools other than NovaPoint, such as road models from Civil 3D and Microstation. This is the description you get when importing 3D lines in LandXML format.
You can build theoretical layers from these 3D lines and perform mass calculations as usual. The method can be set to both manual and automatic mode.
Road Parameters – Manual/3D Lines¶
The road is described with a combination of surface tables and 3D lines.
Example of a combination of surface tables and 3D lines
A pure 3D line description of the road body is static, meaning you cannot rebuild cut and fill surfaces against your own measured terrain.
However, you can solve this with the Manual/3D Lines method, which is a combined method.
Tip
With this method, you can, for example, use 3D lines up to and including the shoulder edge and table values for the rest of the road body, as shown in the figure above.
Common to All Methods¶
The following table can be used for all methods: Broken Slopes
For all methods, you can also check whether the geometry of the centerline in the SFI model meets the requirements in Handbook N100.
Note
The requirements for free road section are checked. Stricter requirements in intersection areas must be handled manually.
Check Against Standard¶
Click Check Against Standard... to check:
- Horizontal and vertical curvature
- Gradient
- Resulting slope (checked only for models with automatic and manual method)
The program reports the following:
- If everything is OK, only a message box is shown.
- If there are problems, a report file opens in Notepad.
Tip
In long section editing and long section presentation drawing, by enabling vertical curvature editing, you can display the deviation of the vertical curvature from the design tables graphically at the bottom of the long section. This is a useful tool to see where the deviations are and what needs to be changed.
Info
See also Road Design in the general user documentation for a detailed description.
Examples of Errors with Explanation¶
Minimum Horizontal Curve Radius¶
- Min. horizontal curve radius [m]: 150.000 (300.000)
Violates the minimum requirement in profile 29.405. The curve (radius) must be increased to min: 300.000
Minimum Clothoid [m]¶
- Min. clothoid [m]: 85.000 (145.000)
Violates the minimum requirement. The clothoid must be increased to A = 145.
Minimum Resulting Slope¶
- Min. resulting slope [%]: 1.000 (2.000)
Violates the minimum requirement. Possible causes: - Superelevation buildup/reduction at the top of a crest/sag (no gradient on the road)
- Superelevation buildup/reduction and the road has little or no gradient
In a superelevation buildup/reduction, the road over a short stretch has less than 2% cross slope. To ensure drainage, you must then compensate by ensuring a gradient in the longitudinal direction.
Solved by moving the curve, moving the crest/sag, or changing the gradient.
The figures below show various examples of resulting slope:
Normal cross slope (drainage is ensured across the road)
Transition to curve (superelevation buildup, right lane rotates around the centerline and is almost horizontal, 0.8%). If there is little gradient, or you are in the middle of a sag/crest, you will get an error about resulting slope.
Full superelevation (8%)
Maximum Resulting Slope¶
- Max. resulting slope [%]: 11.700 (11.300)
Almost the same as Min. resulting slope, but here it is too much. This often occurs when there is a steep gradient on the road + full superelevation. The ratio between gradient and cross slope exceeds the limit values (in this case 11.3%).
Maximum Gradient¶
- Max. gradient [%]: 8.516 (8.000)
Maximum gradient violates the requirements according to the road class.
Minimum Vertical Curve Low¶
- Min. vertical curve low [m]: 800.000 (1000.00)
Violates the requirement. You must make the curve larger. This also applies to "vertical curve high".