Edit your Simulation for a more Accurate Result (6:32 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 at the Analysis in Civil Engineering

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learning path.

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Back in our InfraWorks model on the PO1 local planning

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[INAUDIBLE] proposal, a couple of views have having bookmarked

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to ease the visualization of the areas we will focus on--

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TSA1 and TSA4 four foot traffics are these areas, 1 and 4

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respectively.

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If we check the traffic study area 1, running one

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of its available simulation.

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In example, they will click Simulation.

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We can see the demands of each zone.

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This is the number of trips entering and exiting

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each of the four zones in this particular study area.

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If we hover over any zone, we can

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see that there is a demand in and a demand out,

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exiting the zone, respectively.

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Within the time frame, the simulation

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is set to 10 minutes, in this case.

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You can check the result volumes by selecting,

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for instance, per lane, on our traffic simulation preview

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window.

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When hovering over the bars, we will get the average delay

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and queue length.

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If we choose to turn the result volumes to the per approach

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option, we will get the average delay

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between the delays of each lane for that approach,

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while the queue length will be the maximum shown

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for each lane on the per lane option.

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The bars are coded based on the US highways

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level of service descriptions, so that there

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are six levels of service--

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A, B, C, D, E, F. For blue bars, the service is either A,

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B, C, or D. For red bars, the service falls within E or F.

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As soon as the delay threshold is reduced,

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forcing it to be below the threshold

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set by the level of service D, the bars affected by the change

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will turn red.

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The interesting part is that we can

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edit those demands to adjust them to real world behaviors,

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as having four zones with the exact same demand in and out

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it is highly unlikely in a real world situation.

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That demands will be more likely trips staggered

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over a period of time, a piece of information quite difficult

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to define, because it is not only determined

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by the number of vehicles moving in

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and out of the different zones.

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It is also affected by the types of vehicles,

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the hours of the day the counting

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is being done, the period of the year, the surrounding

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events or maintenance work, features

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such as the mobile geolocation of our phones

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could help gathering this kind of information,

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but privacy data laws tends to block this option.

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As you show, if we open the Traffic Analyst panel,

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we select the demand table and then

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the demands option on the dropdown menu.

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We will open the origin destination demand matrix

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you're seeing at the moment.

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The rows of the matrix contain the origins, and the columns,

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the destinations.

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If I select a row zone, the traffic analyst panel

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will display the possible destinations for that zone

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in red, whereas if I select a cell within the matrix,

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its value represents the number of trips

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going from the row zones to the column zones in yellow.

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Then to derive the totals for trips exiting the row zones,

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and at the bottom, we can see the totals for trips

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arriving to the column zone.

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This type of matrix is called a direct origin destination

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demand matrix because all the trips are defined from

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and to the different zones.

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If we switch to the TSA

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we can observe that there are five zones this time.

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This will make our direct origin destination demand matrix

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a 25 cells one.

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This is a more complex system containing four intersections.

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The cells of the demand matrix of this traffic study area

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have been already edited with the values

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you see on the screen, facilitated by the council

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analysts.

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After syncing on traffic analyst panel,

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they already [? modify ?] a long morning simulation was run,

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and the results are being displayed.

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We have a maximum delay threshold

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of 55 seconds imposed by the local council.

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The south intersection has a good level of service,

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so does the west intersection, but the northeast one

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looks quite bad at the moment.

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Therefore, the design should be amended in order

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to accommodate the real demands.

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Given that the main congestion occurs on the northeast

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intersection, which contains two main highways in the area,

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and that there is a growth expectation

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due to the new development, you will definitely

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like to propose something able to alleviate current

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and future increased demands.

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So let's propose a roundabout on the west intersection to start.

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Do not edit an existing proposal.

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Make sure you create a new pilot proposal to avoid losing data.

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I have already created a parallel proposal

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that has a roundabout and a solution for the northeast

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intersection also.

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That is the PO2 proposal I am selecting at the moment.

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The PO2 proposal has the roundabout

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on the west intersection, and then on the northeast one,

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we have proposed a bridge so that the congestion disappears,

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enabling a fluid flow in both highways.

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To improve the proposal, we could add auxiliary lanes

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to exit and enter the main highways.

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If we ran the same edited long morning

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simulation we have run before on the previous proposal,

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we can easily see the difference.

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Now, the south intersection is more congested

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because the vehicles willing to travel from the west zones

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to the north-south highway are obligated

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to use the south intersection.

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At any time, you can access the traffic analyst panel

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and edit demand metrics.

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Remember to sync under the top left tab called Cloud,

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and then run your sync simulation in InfraWorks

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to observe the results.