Store Page
Cities: Skylines
All Discussions Screenshots Artwork Broadcasts Videos Workshop News Guides Reviews

Cities: Skylines

Store Page
Cities: Skylines > Guides > RichAntDav's Guides
93 ratings
5-Way Highway Intersections Measured and Compared
By RichAntDav
In this guide I look at 30 different 5-Way Intersections that can be found in the workshop. I run each intersection through the same test and measure its performance. After testing all the intersections I can rank them in order of performance.
5
2
   
Award
Favorite
Favorited
Unfavorite
Created by
RichAntDav
Online
Category: Gameplay Basics, Workshop
Languages: English
Posted
Updated
26 Dec, 2020 @ 6:47am
4 Jan, 2021 @ 3:35pm
7,694 Unique Visitors
136 Current Favorites
Guide Index
Overview
Introduction 
Setup 
01 - 5-Way Intersection with Traffic Lights 
02 - 5-Way, Four Lane with Traffic Lights 
03 - Five-way Highway Interchange 
04 - 5-way Highway interchange (for use on very flat ground) 
05 - 5 way Roundabout 
06 - 5 way pinavia 
07 - Timboh's Pentagon Interchange 
08 - Crazy 5-Way Intersection 
09 - Ore Digger 5 way Interchange 
10 - 5-way Highway Interchange 
11 - BP's 5-Way Stack Intersection 
12 - PentaKnot 1.1 
13 - 5 Way Star Stack Interchange 
14 - 5-way JCT-4 
15 - Timboh's U-Pentagon Interchange 
16 - 5-way Nautilus Interchange 
17 - 5-Way Interchange 
18 - 5 way CloverTurbine 
19 - five-lane 
20 - 5 way Turbine + 5 way Rail (No Tunnel) 
21 - Modified Hartford 
22 - 5-way intersection 
23 - 5 way Interchange 
24 - Kapok 
25 - 5-way attempt 
26 - 5 Way Interchange Flower 
27 - Pinavia 5-way interchange 
28 - 5 Way Interchange Pentagram 
29 - 5-way Pentagon Intersection (IMT) 
30 - 5 way cloverstar interchange - Network Extension upgrade 
Also check out... 
Most Efficient 3-Lane Intersections 
Most Efficient 4-Lane Intersections 
Conclusion 
Comments
Introduction
In this guide I look at 30 different 5-Way Intersections that I found in the Workshop. I test each one under the same conditions, and measures it's performance.

To do this testing, I created an intersection testing map (based on this one) but which has lots of small towns around the edges and can easily be made to funnel most of the traffic through a central intersection, in additional to outside city traffic.

I used various mods, including the Network Extensions 2 DLC, Mass Transit, Traffic Manager: President Edition (TMPE) and a small custom mod I developed myself which counts and logs the number of vehicles passing over a road section.

This guide also has an accompanying video to see the intersections in action:
Setup
Vehicle Counting
To work out the score for each intersection I developed a small Traffic Counting Mod which counts the number of vehicles entering the intersection and vehicles leaving the intersection every minute. To do this I designate two different sets of roads, one for leaving the intersection and one for entering. Then it tallys up the entering and leaving counts every minute. To get the final score I get the per minute average for each intersection for the duration (14 minutes) of the test.

To allow me to more directly compare between intersections of different sizes, the road segments that were used for counting were placed quite far from the centre of the intersections, having them in the same place for each intersection makes direct comparisons more correct, but it does introduce a lag, this can be seen in the graphs. The intersections have no output vehicles in the first minute, it's only in the third minute that we can see the output fully catching up the initial input vehicles.

Starting point
To run the tests I created a starting point that I go back to each time for the tests. I didn't just let the game run and swap in new intersections, I also didn't let the game run with dead-ends, this would lead to vehicle confusion and could lead to vehicles de-spawning in the middle of the intersection.

3-Lane Highways and 4-Lane highways
The intersections that are are built for 4-Lane (and wider) highways have an advantage when it comes to traffic flow, they can simply handle more traffic. I couldn't just restrict those intersection to 3-lane highways at their entrances/exits as they were not designed to have additional bottlenecks in those areas. So, I created 2 different scenarios, one for 3-Lane highways and one for 4-Lane Highways.

2 Different Starting points
A key point for these tests is that they are not actually not a single test, it is two different sets of tests, one for the intersections that use 3-lane highways and one for the intersections that use 4-lane highways. I use the same basic road layout and map setup for each of the tests, but because the roads are different, I needed to create two different starting points. I used a high-performing intersection to let both starting points "bed-in" before creating the actual testing starting points. So the 3-lane and 4-lane starting points have had a few days of game time to diverge before the tests themselves started, which means that we shouldn't really compare the 3-lane and 4-lane tests. It looks nice to have them all together in one video, but they are not directly comparable.

TM:PE Lane changing rules:
This is actually the biggest variable in the tests, handling lane merging and diverging. For every intersection I set up TMPE lane-crossing rules for every single road segment in and around the intersection. I set up what I think might be the best rules and let the test run, then I re-run the test if I think I can make improvements. No24 and no30 gave particular problems as the optimal configuration is not obvious, and these ones took many attempts to get a good score. Most of the other intersections took just 2 or 3 attempts at most.

One of the disadvantages of controlling lane changing so tightly is that slower traffic holds up faster traffic because the traffic is usually not allowed to switch lanes. Usually this does not matter as switching lanes in an intersection almost always slows traffic down, I say almost, because there is one big and distinct exception, intersection no.30. This intersection has multiple 3-lane roads to carry vehicles in multiple directions, this allows vehicles to speed up and pass others in the middle of the intersection. Because of these wide roads, this is the only intersection where switching lanes like this can lead to an advantage, which is why this intersection performs better than the rest, although, big caveat, this intersection took a lot of attempts to balance the lane switching to get it to perform to this level.

U-Turns
The Intersections that allow u-turns can have a small but distinct advantage compared to intersections that do not allow u-turns. Because a percentage of the traffic does desire to make a u-turn, if they are allowed to make that u-turn early on, then that traffic can exit the intersection quickly and it also will not get in the way of other traffic trying to merge at another part of the intersection. However, I think that the only interchange where this might be a significant advantage is no15 "Timboh's U-Pentagon Interchange".

Margin of Error
I think this is quite small but I don't have hard numbers, when I get a chance I'll update this section with details.

Efficiency
At the suggestion of a rew readers I added an Efficiency score for each intersection. At the moment I'm using a simple "efficiency = (cost)/(vpm)" calculation. It does the job to convey the importance of having a properly designed intersection instead of just relying on using lots of big roads.

However, I'm not entirely happy with this simple calculation, I think it over emphasises the cost and does not put enough on the vpm value (it also means that the lowest score wins). I don't want to make the calculation too complicated, but maybe something like "efficiencyScore = vpm - (10 * (cost)/(vpm))" would better balance the cost and vpm and it would also mean that the highest score would win. Anyway I'll leave the simple calculation for now and see what the response is...

01 - 5-Way Intersection with Traffic Lights
  • Creator: Bespoke
  • Cost: 4000
  • Size: 20 x 20
  • Levels: 1
  • Road: 6-Lane 2-Direction City
  • peak: 229 vpm
  • Starting Point: 3 Lane
  • avg: 195 vpm
02 - 5-Way, Four Lane with Traffic Lights
  • Creator: Bespoke
  • Cost: 8000
  • Size: 20 x 20
  • Levels: 1
  • Road: 8-Lane 2-Direction City
  • peak: 275 vpm
  • Starting Point: 4 Lane
  • avg: 256 vpm
03 - Five-way Highway Interchange
  • Steam Workshop Link
  • Creator: HJC86
  • Cost: 46980
  • Size: 64 x 64
  • Levels: 3
  • Road: 3-Lane Highway
  • peak: 607 vpm
  • Starting Point: 3 Lane
  • avg: 372 vpm
04 - 5-way Highway interchange (for use on very flat ground)
  • Steam Workshop Guide
  • Creator: Veo
  • Cost: 69360
  • Size: 64 x 64
  • Levels: 3
  • Road: 3-Lane Highway
  • peak: 814 vpm
  • Starting Point: 3 Lane
  • avg: 411 vpm
05 - 5 way Roundabout
  • Steam Workshop Guide
  • Creator: Arisandi
  • Cost: 189787
  • Size: 180 x 140
  • Levels: 4
  • Road: 4-Lane Highway
  • peak: 1096 vpm
  • Starting Point: 4 Lane
  • avg: 460 vpm
06 - 5 way pinavia
  • Steam Workshop Guide
  • Creator: tod_spam
  • Cost: 50570
  • Size: 96 x 96
  • Levels: 2
  • Road: 3-Lane Highway
  • peak: 652 vpm
    [*Starting Point: 3 Lane]
  • avg: 506 vpm
07 - Timboh's Pentagon Interchange
  • Steam Workshop Link
  • Creator: Timboh
  • Cost: 66170
  • Size: 64 x 64
  • Levels: 2
  • Road: 3-Lane Highway
  • peak: 748 vpm
  • Starting Point: 3 Lane
  • avg: 557 vpm
08 - Crazy 5-Way Intersection
  • Steam Workshop Link
  • Creator: Erazaa
  • Cost: 124950
  • Size: 64 x 64
  • Levels: 6
  • Road: 3-Lane Highway
  • peak: 847 vpm
  • Starting Point: 3 Lane
  • avg: 650 vpm
09 - Ore Digger 5 way Interchange
10 - 5-way Highway Interchange
  • Steam Workshop Link
  • Creator: Crys
  • Cost: 48700
  • Size: 64 x 64
  • Levels: 4
  • Road: 3-Lane Highway
  • peak: 868 vpm
  • Starting Point: 3 Lane
  • avg: 719 vpm
11 - BP's 5-Way Stack Intersection
12 - PentaKnot 1.1
  • Steam Workshop Link
  • Creator: mrtree
  • Cost: 60000
  • Size: 64 x 64
  • Levels: 3
  • Road: 3-Lane Highway
  • peak: 863 vpm
  • Starting Point: 3 Lane
  • avg: 776 vpm
13 - 5 Way Star Stack Interchange
14 - 5-way JCT-4
  • Steam Workshop Link
  • Creator: e_motch
  • Cost: 171350
  • Size: 96 x 96
  • Levels: 3
  • Road: 3-Lane Highway
  • peak: 911 vpm
  • Starting Point: 3 Lane
  • avg: 803 vpm
15 - Timboh's U-Pentagon Interchange
  • Steam Workshop Link
  • Creator: Timboh
  • Cost: 62020
  • Size: 64 x 64
  • Levels: 2
  • Road: 3-Lane Highway
  • peak: 976 vpm
  • Starting Point: 3 Lane
  • avg: 804 vpm
Comment:
See the note in the Setup section about u-turn intersections. This intersection in particular has a slight advantage because of this. This isn't necessarily a bad thing, just something to take note of.
16 - 5-way Nautilus Interchange
  • Steam Workshop Link
  • Creator: SkiiBum
  • Cost: 147904
  • Size: 110 x 140
  • Levels: 3
  • Road: 3-Lane Highway
  • peak: 987 vpm
  • Starting Point: 3 Lane
  • avg: 843 vpm
17 - 5-Way Interchange
  • Steam Workshop Link
  • Creator: Soruvisu
  • Cost: 65170
  • Size: 60 x 60
  • Levels: 2
  • Road: 3-Lane Highway
  • peak: 1075 vpm
  • Starting Point: 3 Lane
  • avg: 845 vpm
18 - 5 way CloverTurbine
  • Steam Workshop Link
  • Creator: Arisandi
  • Cost: 177840
  • Size: 160 x 155
  • Levels: 4
  • Road: 4-Lane Highway
  • peak: 1155 vpm
  • Starting Point: 4 Lane
  • avg: 849 vpm
19 - five-lane
20 - 5 way Turbine + 5 way Rail (No Tunnel)
  • Steam Workshop Link
  • Creator: Arisandi
  • Cost: 402480
  • Size: 180 x 215
  • Levels: 4
  • Road: 3-Lane Highway
  • peak: 1073 vpm
  • Starting Point: 3 Lane
  • avg: 886 vpm
21 - Modified Hartford
  • Steam Workshop Link
  • Creator: SkiiBum
  • Cost: 125621
  • Size: 150 x 105
  • Levels: 4
  • Road: 3-Lane Highway
  • peak:1090 vpm
  • Starting Point: 3 Lane
  • avg: 924 vpm
22 - 5-way intersection
  • Steam Workshop Link
  • Creator: QB
  • Cost: 71920
  • Size: 64 x 64
  • Levels: 4
  • Road: 4-Lane Highway
  • peak: 1212 vpm
  • Starting Point: 4 Lane
  • avg: 942 vpm
23 - 5 way Interchange
  • Steam Workshop Link
  • Creator: Arisandi
  • Cost: 114629
  • Size: 75 x 96
  • Levels: 3
  • Road: 4-Lane Highway
  • peak: 1167 vpm
  • Starting Point: 4 Lane
  • avg: 959 vpm
24 - Kapok
  • Steam Workshop Link
  • Creator: nazcor
  • Cost: 75260
  • Size: 64 x 64
  • Levels: 4
  • Road: 3-Lane Highway
  • peak: 1063 vpm
  • Starting Point: 3 Lane
  • avg: 971 vpm
Comment:
This is the highest performing intersection for 3-lane highways, and this intersection took a lot of playing with the lane-changing feature of TM:PE to optimise it for the test. In particular this one took about 6 different attempts to balance the lane merges to get this output.
25 - 5-way attempt
  • Steam Workshop Link
  • Creator: QB
  • Cost: 53360
  • Size: 64 x 64
  • Levels: 5
  • Road: 4-Lane Highway
  • peak: 1265 vpm
  • Starting Point: 4 Lane
  • avg: 974 vpm
26 - 5 Way Interchange Flower
27 - Pinavia 5-way interchange
  • Steam Workshop Link
  • Creator: ifaq
  • Cost: 116897
  • Size: 110 x 110
  • Levels: 2
  • Road: 4-Lane Highway
  • peak: 1529 vpm
  • Starting Point: 4 Lane
  • avg: 1049 vpm
28 - 5 Way Interchange Pentagram
29 - 5-way Pentagon Intersection (IMT)
30 - 5 way cloverstar interchange - Network Extension upgrade
Comment:
The use of wider highways does give this intersection an advantage over all the other intersections, see the "TM:PE Lane changing rules" note in the "Setup" Section. Note, it took a lot of TM:PE adjustments of lane management to get it to perform to this level.
Also check out...
Before I get to the conclusion, please feel free to check out my other, similar guides:


.
Most Efficient 3-Lane Intersections
Note: Lower scores are better, see Setup section for how this score is calculated

In order from Most Efficient to Least Efficient...

  • no.10 "5-way Highway Interchange" by "Crys", Efficiency Score = 67.73
  • no.17 "5-Way Interchange" by "Soruvisu", Efficiency Score = 77.12
  • no.15 "Timboh's U-Pentagon Interchange" by "Timboh", Efficiency Score = 77.13
  • no.12 "PentaKnot 1.1" by "mrtree", Efficiency Score = 77.3
  • no.24 "Kapok" by "nazcor", Efficiency Score = 77.5
  • no.11 "BP's 5-Way Stack Intersection" by "elliot_gus", Efficiency Score = 78.9
  • no.06 "5 way pinavia" by "tod_spam", Efficiency Score = 99.9
  • no.07 "Timboh's Pentagon Interchange" by "Timboh", Efficiency Score = 118.8
  • no.13 "5 Way Star Stack Interchange" by "Gojulas2k", Efficiency Score = 120.8
  • no.03 "Five-way Highway Interchange" by "HJC86", Efficiency Score = 126.3
  • no.21 "Modified Hartford" by "SkiiBum", Efficiency Score = 135.9
  • no.04 "5-way Highway interchange (for use on very flat ground)" by "Veo", Efficiency Score = 168.7
  • no.16 "5-way Nautilus Interchange" by "SkiiBum", Efficiency Score = 175.4
  • no.08 "Crazy 5-Way Intersection" by "Erazaa", Efficiency Score = 192.2
  • no.14 "5-way JCT-4" by "e_motch", Efficiency Score = 213.4
  • no.20 "5 way Turbine + 5 way Rail (No Tunnel)" by "Arisandi", Efficiency Score= 454.2
Most Efficient 4-Lane Intersections
Note: Lower scores are better, see Setup section for how this score is calculated

In order from Most Efficient to Least Efficient...

  • no.25 "5-way attempt" by "QB", Efficiency Score = 54.8
  • no.29 "5-way Pentagon Intersection (IMT)" by "RichAntDav", Efficiency Score = 55.1
  • no.28 "5 Way Interchange Pentagram" by "General Grievous", Efficiency Score = 65.6
  • no.19 "five-lane" by "Hideri Kanzaki", Efficiency Score = 69.6
  • no.26 "5 Way Interchange Flower" by "General Grievous", Efficiency Score = 70.5
  • no.22 "5-way intersection" by "QB", Efficiency Score = 76.3
  • no.27 "Pinavia 5-way interchange" by "ifaq", Efficiency Score = 111.4
  • no.23 "5 way Interchange" by "Arisandi", Efficiency Score = 119.5
  • no.09 "Ore Digger 5 way Interchange" by "Ted Tastic", Efficiency Score = 121.2
  • no.18 "5 way CloverTurbine" by "Arisandi", Efficiency Score = 209.5
  • no.30 "5 way cloverstar interchange" by "FightBiscuit", Efficiency Score = 236.2
  • no.05 "5 way Roundabout" by "Arisandi", Efficiency Score = 412.5
Conclusion
The best performing 5-way intersection overall is no.30 the "5 way cloverstar interchange - Network Extension upgrade" by "FightBiscuit", however, this interchange is very large, expensive and required a lot of Lane Management TLC to get it to perform at the top level. No's 28 and 29 perform pretty much the same and are much smaller and cheaper and also require a lot less lane management.
24 Comments
< >
codewitch 10 Feb, 2021 @ 12:41pm 
@RichAntDav - There are plenty of great assets on the workshop for service interchanges, but since a lot of people don't know the terminology nor is consistent terminology used, it can be a bit harder to fine. But I can already send you a list of ones I know about - including some I use - if you'd like to start with basic "Cross" style (highway to perpendicular arterial) service in your guide. You might need to adjust the map to add local traffic around the arterial instead of external traffic.

It's a very common thing in real life though vanilla and even admittedly the workshop doesn't touch on it as much. Such as A4 or AB Parclos, DDIs, DCMIs, over-roundabouts, dumbbell, or the more common timed light ones we have around all over the US. I'd be more than willing to send over a list (just let me know when and how you'd prefer) of a few examples already up on the workshop
RichAntDav  [author] 10 Feb, 2021 @ 12:13pm 
Hi asterisk11231, I think you've hit on a very interesting niche with the service interchange idea, it's a really useful type of interchange and although there are a few designs out there, from what I've seen there are not great. I'd love to get around to a write-up of them, drop me a reply or a message when you finish yours I'll definitely check it out.
As you can probably guess though I've started off working on comparing 4-way intersections and as I'm only doing this in my spare time it is going to take a while, particularly because there are just so many options.
codewitch 10 Feb, 2021 @ 7:40am 
@RichAntDav I will say #11 is a pretty good base, but I think it's kinda ugly and would definitely like to try a few designs of my own, that I would test on the map & upload.

If you care to, besides 3-way and 4-way (the next obvious ones), service interchanges could be an interesting write-up. There aren't a lot of good ones on the workshop, or at least those that are tend to be larger or harder to find.
codewitch 10 Feb, 2021 @ 7:34am 
@RichAntDav - Did you test 4-way interchanges on the map yet? I know there's a youtube video with Reddit (both CSL reddit and hilariously other non-CSL parts of reddit) appreciation about interchanges but for sake of consistency/comparison, I think testing some 3-way and 4-ways would be good.

As discussed earlier, I think I'm going to design a few attempts at my 4 way + exit based off a good-performing 4-way like a stack or diverging windmill then add either layered or angular (i.e., 45 degree turn), or roundabout-style service exit to an inner-city area
codewitch 10 Feb, 2021 @ 7:31am 
@RichAntDav - don't forget, the "realism" is actually accounted for in other ways, like turning and acceleration for vehicles - especially trucks. Sure, there aren't accidents, but steeper climbs and tighter angles can slow down traffic at high speed. Using anarchy or some node creation tricks the player can avoid in-game restrictions with highways that approximate some of these for you in the mechanics (and for other reasons, like object encroaching (i.e., collision) or terrain, or just simulation math). Some custom ones that try to be more efficient on space can actually slow down traffic with more "difficult" or "complex" TM:PE settings (respawning off, higher sim accuracy, lane AI, etc - these are generally more realistic and more difficult but also make design mean that much more whereas in vanilla you can hit traffic that since the pathfinding is bad there's no good solutions)
RichAntDav  [author] 26 Jan, 2021 @ 2:17pm 
Hi W+M1,
You've got a good point, when playing the game, cost is not really that important. The main thing about using size as a part of an efficiency is that smaller intersections tend to look less "realistic" and although I'm not a "realism" type of player, as it turns out most players are. But I get your point and I think it's interesting, for one, it's a real challenge to create a great performing intersection that uses as little space as possible. Anyway, I'll definitely try to work it in the future.
RichAntDav  [author] 26 Jan, 2021 @ 1:54pm 
Sorry asterisk11231, missed your comment there.
You've got a really good point, most of the 5-ways are designed purely as just highway intersections, however one of them, no.11 "BP's 5-Way Stack Intersection", by "elliot_gus" is the closest intersection to what you describe, to start with 3 of the roads meet at 90 degrees relative to each other, but one of the roads has only 45 degrees between it and the two neighboring highways, I would use this one as a "local" road in the way you describe. That intersection is only 11th in the List, but it's actually pretty decent and would be able to handle the traffic flow in most cities.

CAT8 26 Jan, 2021 @ 1:57am 
I want a separate efficiency rating - by size only, ignoring the cost. Because let's be real here: the city that doesn't just have a million in the bank is the city you didn't leave running long enough. The game isn't realistic in that regard, and that's OK.
codewitch 19 Jan, 2021 @ 7:31pm 
The only time I really feel like I want a 5-way interchange is a combined 4-way network and highway exit. So I don't want a "star", more like a "cross" that combines with a service interchange. Would you have any suggestions on how to go about this?
RichAntDav  [author] 4 Jan, 2021 @ 3:40pm 
Thanks again for the comments folks, And thanks for the suggestion Crys. You are right that it's not strictly fair to compare the 3-Lane intersection and the 4-Lane intersections. So I added two sections to the guide which rank the intersections Efficiency using a simple formula, I'm not entirely happy with the ranking it's given me but it's better than not having it.

Anyway, as always, let me know what you think and I'll see if I can improve the guide if possible.