Frequently Asked Questions (FAQ)
Q. How can I easily tell what traffic flows are on each road?
A. Use the ‘View as colour’ function [View > View as colour]. Check the View as colour On box, select Object type to colour to be Road Segments from the drop-down list and select Parameter to colour as Flow Rate from the drop-down list.
Then click Update View.
The Road segments will now be coloured according to the traffic flow that they carry.
Q. I am modelling a very long motorway improvement scheme. How can I easily load a small part of my noise model?
A. You should divide your scheme into a number of ‘Named Areas’. Firstly, open the Database Previewer and then select ‘All populated tiles’ and click Load. This will load the whole model. Now zoom to the area of interest and with the mouse, click in all the tiles covering that area. Now click Add and in the dialogue that appears, enter a name for the chosen area and click OK.
This will create a new named area and when you load tiles in future, you can select just this area. You can have as many named areas as you wish.
Q. How do I create a new scenario?
A. Firstly use the previewer to download the scenario that is most similar to the new scenario that you wish to create. You should then select File>Commit changes
You will be asked whether you wish to save the changes to the existing scenario or to a new ‘child’ based on the current scenario. Select the ‘New Child’ option and type in a name for the new scenario. The new scenario will then be created. Any changes you make in the child scenario will not affect the parent, but changes in the parent will appear in the child, except where you have already altered that object in the child, in which case it doesn’t change again.
Q. How do I create a noise model automatically from a DXF file?
A. Firstly, you should make sure that the layers in the DXF file have not been compressed into a single layer. Each layer should contain only one type of object. Next, select the layer containing the object type of interest. Next choose Convert Layer from the View menu and follow the instructions. For more detail, look up Convert Layer in the User Manual.
Q. How do I get height details into a NoiseMap model?
A. If your DXF or Shapefile has 3-D co-ordinates, then you can assign the height of the model objects directly from these (see Convert Layer in the User Manual.) Otherwise, if you have already imported a Ground Model (ie Ground Contours) you can ‘drape’ the new objects over the Ground Model. To do this, choose ‘Automatically generate height from NoiseMap Ground Contours’ when importing the DXF or Shapefile.
Q. I have imported some road segments from a digital map, but the direction of traffic flow is wrong on the roundabouts. How can I fix this?
A. Firstly select the segments you wish to correct, then select Segment Tools from the Edit menu. Then select ‘Reverse Segment Chain’ (shortcut key – CTRL+X). The segments will be reversed automatically.
Q. What is the best way of checking that the object heights in my model are correct?
A. To get a quick over-view of the heights of object, use the View-as-colour option from the View Menu. Check View as colour on. Height is the default View-as-colour option, so click Update View and all objects will be coloured according to their absolute height. You can also create a 3-d view, draw a cross-section or label the height of objects on the screen.
Q. How do I calculate noise the coming from different parts of the road network?
A. If you want to know the amount of noise contributed by each source at a receiver, then select the receiver and select Show Segment Contribution from the Calculate menu. If you want to know the noise contribution from different Categories of road (eg, New Road, Existing Road) then you need to assign each segment or other source to a particular Category. See Categories and Combinations in the User Manual.
Q. Why does NoiseMap seem to be ignoring some noise sources?
A. NoiseMap disregards noise sources that are more than the set cut-off distance (COD) from the calculation point. It also ignores line segments that subtend less than the cut-off angle (COD) at the calculation point. Check the settings in Parameters, Edit Global Parameters. Also ensure that the Category of the noise source is included in the Category Combination.
Q. How do I show a noise contour over a bitmap of the area?
A. Firstly, load the Bitmap using the Edit, Load Bitmap function. Then load the noise contour of interest from the Calculate, Load Database Contour function. In the Contour Display Parameters Dialogue, select Draw Method to be White Bgnd (assuming the bitmap is on a white background), then click Apply. The bitmap should now appear behind the contour.
Q. I have changed part of the noise model and now the noise contour has disappeared. Help!
A. When you change part of the noise model, any noise contours that are affected by that change will be marked as ‘invalid’. However, they are not lost. Select the area to download and the type of noise contour. Tiles with valid contours will turn green and tiles with invalid contours will turn red. Tiles without contours will remain purple. To download valid and invalid contours, uncheck the ‘Only load valid contours’ check box, and click load.
Q. I have sent some contours to the calculation queue, but they haven’t been calculated.
A. You need to connect your machine (or any other machine) to the calculation queue. Firstly, ensure that the computer is logged into the correct database and then select File, Connect to Calculation Queue. You will see the tiles being downloaded and calculated on the computer.