Hole Digging Lots (URL so its easier for you to link it http://www.simtropolis.com/forum/files/file/3599-hole-digging-lots/)
Buddybud's Rural Highway Walls (Shown in this tutorial, but there are other choices on the STEX)
Alright lets get started, first we must construct the sunken highway. Once you have downloaded the Hole Digging Lots they will be found in your transit menu like shown in the pic below, scroll down till you find "Hole Digger for Sunken" and place them like I have in the pic below.
Next Step is to drag a road through one of the rows of Hole Digging Lots this will make the lots actually "Dig". It is important to make sure when plopping the hole digging lots that the arrows are facing in the same direction so that the road will go straight through. Do what is shown in the pic below.
Now that you have dragged a road through one side it will be sunken into the terrain, now you need to drag a road through the other row, like shown in the pic below.
This should be your finished product.
Demolish the 2 roads and place 2 Road tiles in the center at the deepest part of the hole.
Now you need to extend your hole by placing individual road tiles starting at the center two and spreading out. For the sake of the tutorial extend it by 6 rows of 2 tiles in each direction and the finished product should look like it does below.
Because it is hard to see the hole with my terrain mod installed I have inserted this pic to show you that all the sides are equally as steep and what it should look like up until now.
Now we need to construct the overpass, locate the NAM Road Puzzle peices which are located in the Roads menu and also dipicted in the picture below. Once you click on the Puzzle Piece you need to press TAB and continue hitting TAB as it scrolls through the different puzzle pieces. Once you arrive at "*T* Road OnSlope Puzzle Piece" place the 2 lots like shown in the picture below.
Once you have placed those directly accross from each other so you can make a bridge, keep scrolling through the Road Puzzle Pieces by repeatedly pressing TAB till you find the "Road over GroundHighway Puzzle Piece" and place it in between the 2 OnSlope pieces and place it right on top the highway and it will fit in nicely.
The finished overpass should look like the pic below. Now we need to expand next to the highway, to do this we add 5 individual road tiles going away from the intersection like shown in the pic below.
Ok, now we have set ourselves up for adding On/Off Ramps. To find the Onramps we need to use for a sunken highway go to the highways menu and scroll to the bottom till you see "Single-Sided Parallel Ramps" and click on it. Now once you have clicked on it hit TAB once and that is the first ramp we will be using. Place one north of the overpass on the right side( if your sunken runs east to west place it on the east side of the overpass). I put my On/Off Ramps on the 3rd road tile so that it will ease congestion. Do so like in the pic below. Once you have placed the north one continute and place the south one on the left side. It may take some tweaking and rotating to get the piece to fit right but it will.
Now that those 2 are placed, while you are still have the Ramp selected press TAB twice and that will bring you to your next ramp that you will use for the other side. Place one on the north end of the overpass left side and one south of the overpass on the right side. Remeber to have the Ramp meet the road at the third road tile. Once again it may take some tweaking and rotating to get it to fit in there.
Now the finished product should look like this.
Drag roads through the points to connect everything and it should look like this.
Now to add some highway walls. We will use buddybud's walls although there are other types. buddybud's walls will appear in the Power Menu like shown in the pic below scroll down till you find the "Sunken Rural Highway Wall 1x1 Road Bridge with OnRamp" and place them one on each side like shown in the pic below.
Now find in the same menu the "Sunken Rural Highway Wall 1x1 Straight Right Transitional Section" like shown in the pic below and place it on the other sides of the pieces you just placed like shown in the pic below.
Now the finished product.
Next we will use buddybud's walls to make the Ramps look nice and blend in with the rest. Scroll down till you find "Sunken Rural Highway Wall 1x1 Right On-Ramp Section" and place them like shown in the pic below one on the North side on the right and one on the South side on the left.
Next use the "Rural Sunken Highway Wall 1x1 Left On-Ramp Section which will be just below the one you just used. Shown in the pic below. And do the same to ther other On-Ramps like shown below.
Now to finish it off add some more transitional pieces and some filler pieces and you are finished, buddybud also has Pedestrian Overpasses that will look nice and you can add those where you want.
The Finished product In-Game with development.
For any questions regarding this article, please PM Crazychickensc12.