Parallel intersection

[t1a2l]

I am looking for a way to connect a main road that goes parallel to a highway. Also there is a main road that comes from north and south also - they all need to be connected. (the road from the south is a cargo harbor and from the north is industrail zone). Didn't find any thing on the workshop so far. Thanks in advance.

[grapplehoeker]

Why not use what is there by default... the highway ramp?

[t1a2l]

Too much conjection...

[grapplehoeker]

Originally posted by t1a2l:

Too much conjection...

I'm sorry, I realise that English may not be your native language.
"conjection" is not a valid word
Did you mean "conjunction" or "conjecture" or perhaps, "congestion"? ;)
If it is congestion, then that is not the fault of a single highway ramp.
A single off ramp has a limited capacity and therefore one would not be sufficient.
With larger volumes of traffic, you will have to think and plan a way to thin it out and disperse it.
You'll have to look at the bigger picture and determine where the traffic is coming from and where it needs to go.
One, two or several interchanges may be required. More than one highway may be required.
So rather than seek to solve it with a single road as an exit from this point on your highway, deal with all of the traffic that has to reach a variety of destinations and provide multiple means for them to reach them.
Since you haven't provided a savegame or a screenshot we can examine, and given your limited description, all I can offer is the conjecture above ;)

[Markus Reese]

I think I understand what you mean. Can you screenshot though? want to see if I am visualizing correct.

[Arkhalis]

I think this is what you want:
https://imgur.com/a/mfAYWfI
Sorry if this is a huge mess. These kinds of interchanges are very complex because they require many different paths (for example: road westward -> highway westward, road westward -> highway eastward, road eastward -> highway westward, road eastward -> highway eastward, etc.)
You don't necessarily need to copy down mine EXACTLY, but it gives you an idea of how you can build the roads and what directions each ramp needs to go to.
As for the 'main road that comes from north south', I don't know what you mean, but you can put a roundabout or something next to this interchange if you want to connect other roads to it.
You don't want to connect too much to the same interchange or else you'll end up with something like this https://imgur.com/a/zXIgjw5 (a crazy interchange I built for fun)

[Jarl Ballin]

Theres many ways to connect roads running parallel to highways. Default intersections as Grapple is talking about still work, and if those are getting too much congestion* then that means you need more access points for that part of the city. The cars will, yes, slow down a lot if you make them enter that parallel road at a 90 degree angle because they have to make a turn, but you can bend the offramps so that they enter the road at a better angle.

Here is an example of what I've done somewhere for "parallel" roads and highways: https://i.imgur.com/B1jcJWz.png

[t1a2l]

@grapplehoeker @twistedmelon @Glue Stick @NordLord -
Here is a picture with explanations:
https://i.imgur.com/XKAdgNZ.png

[me6472]

Your screenshot shows two problems with your interchange:

• The four way junction between the 'city and bus traffic', 'Harbour traffic' and industrial area traffic
  
• The overpass connecting the main road to the highway

Firstly, your four way junction below the highway is acting as a bottleneck, as it can't cope with the large volume of traffic. Generally, you should avoid using four way junctions as much as possible, as they are very prone to congestion. If you absolutely must have a four way junction between two main roads, use a roundabout. They take up more space, but allow for traffic to be constantly moving, which improves traffic flow.

As for the highway on/off ramp, you've gone for the classic overpass layout that is cheap and simple, but can't handle much traffic. This is because it has two junctions that the cars must stop on. When building a on/off ramp, you want something that allows all cars to drive through without stopping (eg, a roundabout), as stopping is very inefficient.

In your case, I think two roundabouts should do the trick. One roundabout replacing the four way junction at the bottom, and another elevated roundabout above the highway. Ensure there is plenty of room between junctions.

As a general rule of thumb, use one-way roads where possible, and minimise the number of junctions. There are a couple of guides on the workshop you can check out too.

[kesat]

I guess you want to fix that traffic jam on your main road?

In that case you are trying for the wrong solution imo, because it's actually an issue due to a single chokepoint for all your traffic. At least from taking a look at your screenshot there's this situation:
a) Goods import to industry (going west) coming from highway/harbor
b) Goods import to commercial (going east) coming from highway/harbor
c) Goods export to your highway/harbor coming from industry
d) Goods exchangee from forrest park to industry
e) Commuters going from east to west
And all this traffic has to pass a single chokepoint right now.

What i would actually try out first:
a) Seperate internal traffic (commuters, commercial & forestry goods) from your external (import/export) traffic as much as possible by putting your highway connection west of your industrial area instead of between your industry & commercial/residential area.
b) Create a direct connection for your forest industrial to your common industrial area.

[mbutton15]

At a guess I would say you have traffic lights on the North/South road where the slip roads join. I would change to stop signals on the slip roads giving continuous flow to the North/South roads.

Although I don't really like roundabouts, I would suggest making the crossroads into a roundabout. Use 2 lanes on the roundabout as I think that gives better flow than 3 lanes !! I'd also make it look like the roundabout at the end of this video, with one-way feeders, rather than just plug straight to 2 direction roads.
https://steamcommunity.com/sharedfiles/filedetails/?id=1375458699

[t1a2l]

Thanks guys! I tried one big round about for the highway and the 4 way and also two seperate roundabouts one for the highway and the other for the 4 way but still alot of traffic is backing up.
Is there a bit more complex interchange I can use?

[Strategy Nerd]

Definitely. This is still one of my favourites:
https://www.youtube.com/watch?v=yITr127KZtQ
And just knowing how intersections work, you can create your own custom one with only a little planning.
There are a ton of short videos that just show the basic concepts of a high-flow intersection, and you can then apply that information to your own. This way is, in my opinion, better, because next time you run into the problem you'll be able to solve it yourself!

[t1a2l]

Thank every one for the feedback I will try some of the solutions presented here..