TMPE and traffic %

[wilky]

I recently downloaded TMPE for the first time, but I've started to notice some weird things. (Note: I have vehicle despawning currently set to "disabled" aka easy mode, but that shouldn't even matter at the tiny populations I'm talking about here.)


For one thing, on my last city this weekend, I noticed that it's always been in the mid 80% range for traffic even from the very beginning. For instance, I have one save at 2,200 population where all the streets are green (they are two-lane roads, not even dirt roads!) yet the traffic says 86%.

I have another save (different city) at 17-18k population, and upon loading the traffic says 80%. Pretty poor, right? There are some reddish roads and I think I have one stoplight, but everything is flowing and nothing is backing up anywhere.


So if I disable TMPE and reload the first save at 2k population, the traffic immediately jumps to 96-97% after a few seconds, as you would expect for such a tiny town. And the second city at 17.5k population jumps to 88-89% traffic. (This city was made a few weeks ago before I downloaded TMPE, so there are no custom traffic modifications/intersections at play.)


How exactly is traffic % calculated? And more importantly: Why does enabling / disabling TMPE cause the traffic to jump up or down by ~10%? This appears to cast some doubts on TMPE...

[Schawafelschwamm]

Originally posted by me22ca:

Regardless of TMPE or vanilla, the traffic percentage really isn't all that useful of a metric.

You can always just add a bunch of unused roads to make it go up. And the things that make it go down aren't necessarily bad.

Right? I mean, as long as there are no major issues with goods being delivered when they are needed and service vehicles finding their way, there's not much of a reason to 'fix' your traffic., even if the traffic percentage is below 80%. I've had cities with about 75% traffic flow without any major issues (mostly problems with cars stopping while searching for a parking spot).

[Clunk]

I use TMPE extensively across all my maps and barely a piece of road exists where I haven't been at it with TMPE for something. I employ all its functions and the game would be a midnight shadow of itself without TMPE, for me.

My traffic percentage most commonly hovers between 68 to 72% but there are no jams. Queues, yes - but no jams. I have numerous sets of timed traffic lights where patient drivers await their turn. Nice and red on the traffic map within my Holy City. Perfect ✔

Too much attention is paid to the actual percentage figure. I would enjoy seeing a little mod which adds to (or replaces) the percentage display with a traffic light system of red, amber, green where you can set the % for it to switch between colours to indicate a real traffic issue pertaining to your own map and requirements. Such as a broken down or stuck vehicle (yes, they do exist), or where a pedestrian has decided to stand in the middle of a road causing delays.

There are many pleasures with playing CSL. Controlling heavy traffic through a relatively realistic city reliant on enormous industry areas is my passion.

Abrupt changes of road type to accommodate traffic control are not. Vanilla just doesn't cut it when it comes to traffic control and an apparent hit to the displayed traffic percentage by using TMPE is an irrelevance.

[MarkJohnson]

Originally posted by Schawafelschwamm:

Originally posted by me22ca:

Regardless of TMPE or vanilla, the traffic percentage really isn't all that useful of a metric.

You can always just add a bunch of unused roads to make it go up. And the things that make it go down aren't necessarily bad.

Right? I mean, as long as there are no major issues with goods being delivered when they are needed and service vehicles finding their way, there's not much of a reason to 'fix' your traffic., even if the traffic percentage is below 80%. I've had cities with about 75% traffic flow without any major issues (mostly problems with cars stopping while searching for a parking spot).

Not necessarily, the game has a limit of 16,384 (16k) worth of vehicles. It is very easy to reach this limit if you're not careful and it will lag your city hard, then it will crash your city as service vehicles will be unable to spawn and collect dead, and raw materials to be delivered to industry, not to mention goods not being delivered to commerce.

Short travel distances are the key, so vehicles get off the roads ASAP, as this keeps vehicle counts low.

The earlier you optimize your road networks to match your districts, the easier it will be to grow your city to maximum size.

This is more late game advice, than early game advice. But it's hard for new players to see this optimization as necessary.

[me22ca]

Originally posted by Clunk:

Too much attention is paid to the actual percentage figure. I would enjoy seeing a little mod which adds to (or replaces) the percentage display with a traffic light system of red, amber, green where you can set the % for it to switch between colours to indicate a real traffic issue pertaining to your own map and requirements. Such as a broken down or stuck vehicle (yes, they do exist), or where a pedestrian has decided to stand in the middle of a road causing delays.

Honestly I'd just say skip calculating the number at all -- don't show it in the UI, don't have a traffic light system based on it, etc. The fraction is fundamentally useless because more empty roads doesn't actually mean the traffic is better, but that's how the percentage seems to work.

I'd rather notification icons of "traffic on this segment is so bad that a vehicle was despawned" or "this vehicle's trip is taking more than 3x longer than it should" or similar.

[wilky]

I really wish the base game would allow you to clean up lane changes at nodes and intersections (e.g., how you can use TMPE to create dedicated turning lanes and "keep moving lanes" at intersections to reduce collisions). That's really all I wanted to use TMPE for. Maybe the yield signs, too.

Edit: Oh yeah, and I guess the ability to disable crosswalks was pretty useful, too.

[MarkJohnson]

The best way to fix those collisions is to reduce traffic. It takes some doing, but you need to optimize your layout. balancing jobs/workers ratios per district, balancing freight from commerce/industry, balancing import/exports, creating tourist traps to keep tourist isolated in a district. etc. no dead end roads, island districts, interconnecting districts so traffic can flow through it, instead of around it. avoid one-way streets that detours traffic and keeps them on the road longer.

If you post a saved game, I'm sure there are plenty here that will look at it and offer a lot of advice for optimizing your layout.

[wilky]

Originally posted by MarkJohnson:

The best way to fix those collisions is to reduce traffic. It takes some doing, but you need to optimize your layout. balancing jobs/workers ratios per district, balancing freight from commerce/industry, balancing import/exports, creating tourist traps to keep tourist isolated in a district. etc. no dead end roads, island districts, interconnecting districts so traffic can flow through it, instead of around it. avoid one-way streets that detours traffic and keeps them on the road longer.

If you post a saved game, I'm sure there are plenty here that will look at it and offer a lot of advice for optimizing your layout.

My most recent effort was trying to play on the Archipelago vanilla map (I think it's from Natural Disasters). I don't even think it's even worth looking at. I just gave up and decided the map is ♥♥♥♥.

[wilky]

Or here's another example. I made this Parclo A4 service interchange in the Asset Editor, and I think it's pretty compact and nifty, but this is useless in vanilla Skylines without forcing the traffic to right-turn-only at the intersections:

https://steamcommunity.com/sharedfiles/filedetails/?id=2484208027

In order to recreate this such that it would work under vanilla lane rules, I would have to split the arterial into a pair of one-way (elevated) two-lane roads. It would be a mess, and so large/ungainly that it would be impractical to use.

[MarkJohnson]

That's the price of making custom content. But I'm not sure why you need to restrict any traffic?

[MessengerOfRage]

Originally posted by MarkJohnson:

...But I'm not sure why you need to restrict any traffic?

maybe you are not sure because you don't have the TMPE-experiance to see it?
TL:DR to remove vanilla eyesores and make beautifull builds work, in this case TMPE will help remove crossing points.

I appreciate your vanilla knowledge and agree that one should know the vanilla behaviours -and every single mod one wants to implement- before using mods to change mechanics. Your constant agenda of mods are allways bad is "funny" at best, mods are just overly complicated tools, make sure you know your tools and all is well.

in the given thumbnail I see multiple places where TMPE will help reduce crossing points.

for example if a car enters the thumbnail from the left side on the highway and wants to go to the top edge of the thumbnail it has 2 routes to choose from.
a shorter one that needs to cross over the avenue
(take the off ramp, take the right arm at the split, left turn at the intersection)
and a longer one that prevents them crossing over the avenue.
(take the off ramp, take the left arm at the split, right turn at intersection)

in this build vanilla would prefere the shorter path with the crossing of different traffic streams.

yeah you can reproduce simmilar behaviour in vanilla but it will not look the same.
you can eighter change the setup to something ugly and make it work in vanilla or use TMPE to make the beautiful setup work.

like Clunk said there is a multitude of goals available in this game.

Originally posted by Clunk:

There are many pleasures with playing CSL. Controlling heavy traffic through a relatively realistic city reliant on enormous industry areas is my passion.

my passion is to create stunning views while I make the game look realistic.

Mark, while I admire your "vanilla stresstest city" you keep flexing.
Creating allways bigger vanilla cities is not the only way to play this game.
To me that style gets old fast.

[wilky]

Originally posted by MarkJohnson:

That's the price of making custom content. But I'm not sure why you need to restrict any traffic?

The point of the Parclo A4 is that it's a compact service interchange that is able to handle very high volumes of traffic because it's essentially a free-flowing interchange. Here is the diagram with TMPE lane restrictions:

https://steamcommunity.com/sharedfiles/filedetails/?id=2484413049

Note that I also forgot to put some lane restrictions on the tiny intersection above the main one, but that is mostly a non-issue. The important intersection is this one, and the equivalent one on the opposite side (far left screenshot).

Without TMPE, the main problem is that cars will turn left through that main intersection, which screws everything up. (The entire purpose of the longer, looping underpass is to force them to turn right from the opposite side... in real life at least that's how it works.) But even without TMPE, the pink and the red will collide with one another because vanilla Skylines allows "red" to change lanes and collide with pink's lane. Same with blue/purple.

[me22ca]

Originally posted by MarkJohnson:

But I'm not sure why you need to restrict any traffic?

Because the vanilla pathfinder often does unrealistic things.

Believe me, I'd love to never use TMPE again. But right now, using it for the occasional lane arrow tweak or hugo-connector is the best way to fix the pathfinder silliness, for things like traffic that tries to turn left across 5 lanes of traffic just to save going 8 m further.

Even on two-way streets I'll often take different routes to somewhere and back again because left/right turns make a difference. But CSL seems to ignore that kind of thing.

[MarkJohnson]

Originally posted by Coookyman:

Mark, while I admire your "vanilla stresstest city" you keep flexing.
Creating allways bigger vanilla cities is not the only way to play this game.
To me that style gets old fast.

The point of the stress test city was for showing the agents limit of 80k. Mostly for people asking about the max PC they could build to fully take advantage of the game.

But you can see at +600k/25-tiles the vehicle limit is maintained, while it is easy to hit the 16k vehicle limit in under 100k pop city on only 3 -tiles. It goes to show traffic issues are not road nor population related, but zoning related. Fixing roads will not fix your traffic issues. You will still have insane traffic in your city.

Yes, I know I over use this statement, and a few users have figured it out and understand what I mean, But it is hard to explain as there is so many micro-interactions in the game, it's tough to explain it all simply and plainly.

For the record, I'm not against modding the game. I mean, I use mods to make a 25-tile city as 9-tiles are the default.

My pet peeve is installing mods to fix problems, as they don't fix the problem at all and mask it over until it breaks the city down the road (pun intended), usually beyond repair (or easier to start over than fix)

[MessengerOfRage]

Originally posted by MarkJohnson:

For the record, I'm not against modding the game. I mean, I use mods to make a 25-tile city as 9-tiles are the default.

thank you

Originally posted by MarkJohnson:

My pet peeve is installing mods to fix problems, as they don't fix the problem at all and mask it over until it breaks the city down the road (pun intended), usually beyond repair (or easier to start over than fix)

I agree, using mods without understanding what they modify will lead to problems later.