Sunken Highway Trick

[thegynophile 0]

 OK, so, I notice in some screenshots and videos that some people have done this very cool trick with their downtown areas where they build a sunken highway that periodically goes into a tunnel to allow buildings to be built above, then reemerges to toss out a couple on/off ramps to parallel roads.

My question is, how do I do this? I know how to build sunken highways, but whenever I do this I wind up with this big hump in the middle of the exposed part. Is there some trick to using the hole digger lot, or is there a special digger that I don't know about?

[RedImperator 16]

There's a digger called "Hole Digger for Sunken", which will dig a 15 meter hole. Unfortunately, it's only one tile wide, so you'll have to widen it with the street tool. That should make your sunken highway perfectly flat going into and out of tunnels. Now, another possible issue is with your on/off ramps. There are two different ways to do it, and one of the tools (which I think is a Maxis default) looks terrible, with a hump in the highway and the overpass doing a stupid and ugly up-and-down thing. The problem is those ramps aren't 15 meters deep, so they pull the highway up towards street level and (for some reason) make the overpass jagged.

The second way to make interchanges is with the single sided parallel/perpendicular ramps that the NAM adds to the highway menu. These are fifteen meters high and, assuming you used the "hole digger for sunken" tool and the service roads are level, they will be perfectly flush with the surface streets without any adjustment. The NAM overpass puzzle pieces are also designed to be 15 meters off the ground, so if you have everything terraformed properly your sims will have a perfectly smooth and level bridge across the highway and a perfectly smooth and level highway below.

This is probably easier to illustrate with pictures. I'll see if I can put some up tomorrow.

[ArchangelMichael 51]

Have a look at this tutorial.  Also, I recommend using a diagonal jagged edges mod, a slope mod, and Shadow Assassin's hole digging lots.  Be sure to read the ReadMe files for each.  To download those, you will have to register at the LEX if you haven't already.  The LEX contains the highest quality custom content (there's been an awful lot of spam on the STEX lately) and typically has much higher download speeds.

[mayor_brando 8]

Originally posted by: RedImperator

 There are two different ways to do it, and one of the tools (which I think is a Maxis default) looks terrible, with a hump in the highway and the overpass doing a stupid and ugly up-and-down thing. The problem is those ramps aren't 15 meters deep, so they pull the highway up towards street level and (for some reason) make the overpass jagged.quote>

The solution to this is to dig 15m, then raise the terrain a little bit and you won't get those nasty bumps.

This is an example. I think it looks pretty good, with only one minor bump on the overpass.

[RedImperator 16]

Originally posted by: mayor_brando

Originally posted by: RedImperator

 There are two different ways to do it, and one of the tools (which I think is a Maxis default) looks terrible, with a hump in the highway and the overpass doing a stupid and ugly up-and-down thing. The problem is those ramps aren't 15 meters deep, so they pull the highway up towards street level and (for some reason) make the overpass jagged.quote>

The solution to this is to dig 15m, then raise the terrain a little bit and you won't get those nasty bumps.quote>

Yeah, but that's a lot of fiddly, frustrating work and it still doesn't look as good as the puzzle pieces, especially if you have buddybud's walls and bridge skins.