Model a road corridor

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In this session,

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we will use the alignments profiles and assemblies

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we developed previously to create the corridor model.

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We

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will demonstrate a few procedures when modeling the

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corridor that we can implement on other projects.

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Before we get into the corridor,

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there are a few details that we need to verify regarding our assembly.

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We need to be sure that we have enabled super elevation for the lanes.

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We can select the lane and specify that we want to use super elevation

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and for each lane, we can identify if the lanes are left or right or inside or outside.

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We can also determine the direction of the slope

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either toward the crown or away from the crown.

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This will depend on our assembly configuration

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and the method of super elevation used in the corridor.

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The next item to consider prior to creating a

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corridor is to apply super elevation to the alignment.

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First, we need to apply a design speed to that alignment if we have not already done.

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So

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here we set the design speed at 45 miles an hour.

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We will select the alignment again and choose super elevation from the menu

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and we can choose to calculate. Now,

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we have a few choices for this corridor.

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In this case, we will choose divided crown with median.

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We can also modify the pivot method for this. We'll choose the center

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where the crown will be between the two lanes.

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Next, we'll define the number of lanes and the lane widths.

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And then we can also control the outside shoulder and the super elevation criteria.

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And we will choose the library that is included with civil 3d.

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But we could choose a custom file here if we needed to.

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When the calculation is complete,

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we can view the results and modify the stations and slopes if needed.

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We can also see that those items have been labeled in plain view.

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Now, let's jump into the corridor here.

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We'll specify the name which baseline alignment we want to use

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the profile and the assembly that we'll use in the corridor.

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We'll choose the target surface and then select. Ok.

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Now keep in mind we can modify any of these items later on. If we need to

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within the corridor parameters,

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we will set up items like the frequency of the sections and some of the key targets

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in frequency.

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One of the items that I like to choose is to apply by curvature to the curves.

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This helps to model the corridor more accurately

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and avoids a segmented look in tighter areas.

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Surface is already defined for our target.

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And in this case,

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we don't have any feature lines or alignments to define our pavement lines.

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Once we run the corridor, we want to inspect it and make any necessary revisions.

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We can view it with the section editor.

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This gives us plan profile section and assembly view of the corridor

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and we can also modify these windows. But for now, we'll use this format.

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So in the curved section,

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we see that we have defined our assembly

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lanes incorrectly by looking at the super elevation.

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So we can fix that easily by redefining the parameters in the assembly.

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In this case, we need to make it toward the crown instead of away.

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Then we rebuilt the corridor

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and those lanes much look much better.

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Now,

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let's look at some of the other areas of

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the corridor and verify that they are correct as well

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and those also look pretty good.

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So let's change the viewport configuration to three windows so that

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we can zoom in on the section view by zooming in.

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We see that that looks pretty good so we can move on to the next corridor.

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So we want to model this access road so that we

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can eventually set up the intersections for the other corridors.

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For the purposes of this demo.

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We won't use super elevation on this segment,

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but we would do the same thing that we did.

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Previously,

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we will apply the assembly with the retaining walls for this corridor

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and then we'll define the corridor elements

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and update the frequency

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here. We actually want to divide some of the regions near the intersection.

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So we'll turn off the target surface at the intersection.

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So once those are all set, we'll run the corridor

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and now we'll view the results using the section editor here as well.

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Once we have these corridors, let's add the east and west alignments.

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We'll add super elevation as an undivided crowned roadway this time,

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similar steps as the previous alignment by defining

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some of these items for the calculation.

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And with a reverse curve,

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Civil 3d has identified a number of conflicts

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or overlaps in the super elevation calculation.

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So we can either manually adjust these stations or we can select these right,

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click on them

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and choose automatically resolve overlap

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and then these values will be recalculated to accommodate the reverse curve.

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And then we'll also calculate the super elevation for the east alignment.

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Now, in this corridor,

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there are a few items that we want to

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do that are slightly different than the previous corridors.

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We will choose the west alignment as the baseline in the West Assembly.

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Then we'll split the region up as we did previously

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and then update those targets

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once we have that, let's run that so that we can view the limits.

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This seems to be ok for now, we have quite a bit of cut in this particular section,

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but let's go back into the corridor parameters

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and add the east alignment

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and we'll do this by adding a baseline.

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So we need to determine the profile

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and the assembly for this baseline.

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And for this part, we'll add the East assembly

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and we can split the regions here as well,

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then rerun the corridor

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as we did before we can check the results in the section editor.

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So it looks like we do need to make some changes

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and then rebuild the corridor

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in cases where we need to redefine the assembly parameters.

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We can right click on the assembly and go to the assembly properties.

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This window gives us the same ability to

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edit the sub assemblies as the properties window.

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So if the section looks incorrect,

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we'll likely need to modify the super elevation either inside

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or outside or we'll need to modify the slope direction

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and that looks to be correct. Now,

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we then choose the other baseline that we

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want to track along and then view those results

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again, we can make any needed corrections as we move along the corridor.

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Everything looks to be in good order here. So let's move to the next one.

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Now, the next corridor utilizes the offset alignments that we created previously.

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So we want to use feature lines or poly lines to control the rays medium locations.

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We could use alignments

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but this line work will be sufficient.

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So we set up the assembly previously with a link

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between the southbound and the northbound lanes with a median

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and with median turn lanes.

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We also really need to note the direction of the stationing. In this case,

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southbound is on the right side of the assembly.

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Once we've set those items previously discussed, such as frequency and targets,

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we can now focus on some of the other targets.

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This is where identifying the lane names is critical.

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First, we'll set the offset alignment as the northbound offset alignment

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and the profile as the northbound offset alignment profile.

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So let's run the corridor now

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to verify that we're in the right place with the alignments and with the lanes.

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So by inspecting those look to be pretty good,

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we also have an additional assembly without the raised

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median that we intend to use near the intersection.

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So we can split the regions and then set the corridor with the additional assembly

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for the median control lines.

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We'll choose

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items from our drawing

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here. We can pick the poly lines that represent the median on both sides.

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This is where knowing our right and left lanes

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and the southbound and northbound lanes is vital.

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So the median looks to be pretty good looks like it's modeled it fairly well.

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We will need to update the intersection area. But for now, the region looks ok

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south of the intersection, we'll do the same thing

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where we identify the control lines with poly lines from our drawing.

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Now, at the end of the corridor, we extended past the median.

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We can truncate this by revising the region's station limits.

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And now that looks pretty good too.

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Now, in the section editor,

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we want to look at the transition areas

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to ensure that our assembly is behaving correctly.

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The median looks pretty good,

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but we do have a gap near that intersection.

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We can resolve this in a couple of ways.

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We can either create poly lines between the sections to target horizontally.

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But one thing that we need to consider is the elevation,

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The assembly will target this in plan view,

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but it will project the slopes as they are set.

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And in this case, we can see that we are off

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the other way that we can resolve. This

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is to use the center line alignment

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as a horizontal and vertical control.

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So once we set that

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we can inspect the section view and that has been drawn correctly,

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and we can even see that it has corrected the slope to

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the target center line alignment and filled in those gaps nicely.

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The final element is the turn lane for the northbound side.

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And we have a polyline that represents the edge of

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travel lane that we will include in the corridor.

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Again, we need to pick the lane that will target the line.

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Then we select the line from our C AD file and we rebuild the corridor.

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The section view shows the lanes nicely.

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So these are some of the typical methods for creating corridors.

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Oftentimes we'll have to use a combination of these workflows

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to get the exact results that we're looking for.