Run a Simulation Flow (5:49 min)

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GOYO GRZESKOW: In this video, we will run several traffic

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simulations on your model to either support our proposal

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or amend it accordingly.

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This is where we are in the roads and highways

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conceptual design learning path.

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Now, starting where we left it in InfraWorks,

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let's start bookmarking a reference view.

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Let's add it and call it General View.

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It's a useful way to keep the same perspective

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through all existing and new proposals.

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I have already added a new proposal

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based on the PL1 local one.

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I named it PL1 local planning road.

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The difference with the regional one

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is that the new planning road has

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been outlined above the existing component

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road that runs through the development that we proposed.

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You might be wondering why that overlapping was introduced.

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Well, the reason could be that the original design had

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too many unjustified earthworks impact in the final budget,

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and we were required to give a [? leveled ?] alternative.

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The planning roads can be easily draped to the original train

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layer by right clicking on them and selecting the drape feature

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option.

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If we do not select that option, the planning road

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will be laying on the component road, matching its levels.

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Let's now delete the component road keeping the planning one,

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then switch to InfraWorks Analyze tab

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and clicking on traffic simulation icon.

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You will notice that as soon as the traffic simulation icon is

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selected and there are no previous traffic study areas,

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the types of roads supporting traffic analysis

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are highlighted in light blue.

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And we can then start to draw the perimeter of our traffic

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study area number

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to start the first and next [? parenthesis ?] of the area

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and double left clicking to finish it.

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If within the perimeter drawn, InfraWorks

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detects planning roads, a window prompting

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to change them to component roads

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will appear unless you have previously

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chosen to opt out and not see this kind of messages again.

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Note that the planning roads are highlighted in red,

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as they are not able to be analyzed by traffic simulation.

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That's why the zones--

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the big blue boxes--

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are not automatically displaying over them

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as it happens with the component roads.

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Because of the way it works, traffic simulation

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will only display trips from and to the demand zones.

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This means that the vehicles will move only

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between the blue boxes through component roads,

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ignoring the planning roads despite being the shortest way.

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Traffic study areas are not only limited to small intersections.

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In fact, this powerful tool is able to analyze

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very complex roads and highways ramifications

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with elevated number of demand zones.

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Note that the message prompting to convert the roads

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is optional, as we might not want

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to consider a particular road for different reasons.

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For example, if that road has no relevant traffic flows.

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In order to have a fresh start, once all the previous study

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areas are deleted, let's convert our planning road

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into a component road and define the intersections that

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are as important for the traffic simulation

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as having component roads instead of planning roads.

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When defining an intersection, make

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sure the last point of your component road

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is properly dragged through the center

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of the crossing component road, unless it's

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a continuous road, in which case you need to make sure

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both are crossing at the same level.

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Now that we have our intersections and roads

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defined, we are ready to create traffic study areas.

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Because we need a detailed overview of the traffic

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flows in the area, we will create one traffic study

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area per intersection and then a global one that

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will contain the previous ones to get

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a good understanding of the impact of each

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on the whole system.

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As we outline in the perimeter of our study areas,

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we can see that the demand zones are being correctly auto

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displaying both the roads if not too close to the intersections.

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Also, once a simulation is run, we

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can see that the [INAUDIBLE] flows are correctly

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entering or exiting to and from all the zones available.

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At the moment, the second traffic study area

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is being created.

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In some cases, as it happens on the third traffic study area,

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will see that extra adjustments are required

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to address inconsistencies when simulations are being

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displayed, such as the overlapping of cars

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when stopping at lights.

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To finish, let's create the fourth traffic study area

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containing all the previous intersections we have already

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set to analyze individually.

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If for whatever reason one of the zones is missed,

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grab one of the vertex to adjust and make

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the blue box to appear again.

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Remember that the demand zones are

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governed by predefined number of trips

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going in and out of that zone.

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In this study area, we have five demand zones

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that determine the reach and destination demand matrix.

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This matrix defines the number of trips

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in and out of its demand zone.

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Number of cells of the matrix equals the number

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of zones squared, 25 in the case of the fourth traffic study

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area.

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By right clicking on the canvas, we can exit the Traffic Analyst

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panel [? or ?] the origin destination demand matrix

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can be edited.