Revisiting the Traffic Simulator: Multimodal Transportation Opportunities

[Lucario Boricua 7,050]

Today I want to announce a special project for the Network Addon Mod, we'll re-visit the Traffic Simulator to refine it and tune it for multimodal transportation behavior!

To carry out this project, we'll be forming a focus group consisting of both players, and NAM team members and associates alike. My intention is for us to test out which variables need adjustment to recreate more realistic commute behaviors in settings with significant transit availability, while also keeping undesirable commute behaviors at a minimum. Results from this testing may lead to development of new NAM features for everyone's enjoyment. 

 

Spoiler

Project lead: @Lucario Boricua

NAM Team Members: B22rian (SC4D), @Tarkus @z1

NAM Associates: @ulisse, @Naomi57, Eric Blair (SC4D), CasperVG (SC4D) @matias93

 

Spoiler

@chfzdn

@Leo --

Still looking for volunteers!

 

Spoiler

Looking for volunteers!

 

How to get involved: community members interested in participating can post publicly in this topic, contact me directly through private messages (Simtropolis and SC4 Devotion), or through the respective Discord servers of ST, SC4D, and Rob's Red Hot Spot. Depending on the interest and skill level, I can arrange the provision of pre-edited versions of the Traffic Simulator files, or teach the participants how to edit the changes in themselves.

 

Required tools: either iLive Reader 0.9.3 (link here) or SC4 Reader 1.5.9 (link here)

Useful resources: 

• Tutorial: Understanding the Traffic Simulator, (SC4 Wiki article) by @z1
• Topic: A Guide to the Operation of the Traffic Simulator, (SC4 Devotion forum topic) by @z1
• A Guide to the Operation of the Traffic Simulator, (Simtropolis forum topic) by @z1
• NAM Unified Traffic Simulator and Data View Help, (SC4 Devotion forum topic) by @z1

 

Which variables of the traffic simulator are we experimenting with?

• Network speeds of the travel types: the traffic simulator defines the speeds of the various travel types (the travel modes) on each network. For the first round of experimentation, we will focus on the speeds associated with street transit types, namely pedestrians, cars, buses and freight trucks. Of interest is making streets meaningfully distinct from the other surface road networks. At present, I'm aware numerous players ditch streets altogether, as they treat them as inferior roads in terms of their functionality. A slight increase of pedestrian speeds and decrease of motor vehicle speeds can have positive effects in realism of travel behavior. This can minimize rat running (cars using local streets to bypass congestion), routing of buses and trucks only along higher hierarchy roads (more realistic bus and truck routes), and increasing the catchment area of transit stops (thus more realistic bus and train station spacing). A derivative project which could be done with these tweaks is creating a second override system for Streets, without motor vehicle paths, to create a draggable pedmall system.
   
• Trip Starting Cost by Travel Type: the traffic simulator can add time penalties or handicaps to starting trips using a particular mode or Travel Type. Of interest is tweaking the starting cost for car trips, as this can mitigate the issue in which car trips outperform walking in super short distances, and at the same time increase the catchment area of transit stops, specifically in the vicinity of the residential areas and the start of commute trips.
   
• Adding pedestrian paths to rail networks: as crazy as it sounds, there is a possibility of creating entirely new networks by adding or removing paths as part of an override system, while also setting different speeds to those used in the networks traditionally associated to them. This area requires bigger modifications elsewhere, but it remains as an option to expand the game's capabilities. Projects similar to this concept include the Hybrid Rail (dual networking of rail and monorail/HSR, including paths for both), the Real Highway (removing pedestrian paths from the Dirt Road, to create a versatile and realistic freeway/motorway network), and the Subway RHW FLUPs (overriding subway with Real Highway). My proposal in this area is using the Elevated Rail to create a cycling network through an override system, such that we could use the El-Rail tool to build a network with pedestrian paths and set to support a significantly higher speed than the walking speeds programmed into the surface road networks (Street, Road, OWR, avenue). We still need to research if such configuration even works, as there's known issues with incompatibility of certain networks with paths other than those explicitly intended for it.

 

How will testing start?

We'll start with the first two topics, network speeds of the travel types and trip starting cost by travel type. With these two tweaks, we expect to modify commute behavior in the game to recreate more realistic transportation behavior for pedestrians in multimodal transportation networks. Additionally, players who want to recreate pre-modern cities before motor vehicles and railways became a thing can also benefit from our findings to do their respective traffic simulator tweaks.

 

Spoiler

Network speeds for streets, km/h:


--BASELINE--

Pedestrian	15	(0)
Car		30	(0)
Bus		25	(0)
Truck		25	(0)



BATTERY I: Double offset			BATERY II: Slower vehicles			BATTERY III:	Faster pedestrians

	--TEST A--					--TEST D--					--TEST G--

Pedestrian	18	(+3)			Pedestrian	15	(0)			Pedestrian	18	(+3)
Car		27	(-3)			Car		27	(-3)			Car		30	(0)
Bus		22	(-3)			Bus		22	(-3)			Bus		25	(0)
Truck		22	(-3)			Truck		22	(-3)			Truck		25	(0)

	
	--TEST B--					--TEST E--					--TEST H--

Pedestrian	17	(+2)			Pedestrian	15	(0)			Pedestrian	17	(+2)
Car		28	(-2)			Car		28	(-2)			Car		30	(0)
Bus		23	(-2)			Bus		23	(-2)			Bus		25	(0)
Truck		23	(-2)			Truck		23	(-2)			Truck		25	(0)

	
	--TEST C--					--TEST F--					--TEST I--

Pedestrian	16	(+1)			Pedestrian	15	(0)			Pedestrian	16	(+1)
Car		29	(-1)			Car		29	(-1)			Car		30	(0)
Bus		24	(-1)			Bus		24	(-1)			Bus		25	(0)
Truck		24	(-1)			Truck		24	(-1)			Truck		24	(-1)	

 

 

Gonna provide the full batch of modified Traffic Simulator Z capacity options here for all players, for those who haven't done the modifications themselves. All the files uploaded here correspond to Test Battery A, make sure to mention that whenever you post screenshots and your observations on the results. These files are available for any player interested in participating, we look forward to seeing your results and experience!

 

 

NetworkAddonMod_Traffic_Plugin_Z_TestA_Classic.dat

NetworkAddonMod_Traffic_Plugin_Z_TestA_High.dat

NetworkAddonMod_Traffic_Plugin_Z_TestA_Low.dat

NetworkAddonMod_Traffic_Plugin_Z_TestA_Medium.dat

NetworkAddonMod_Traffic_Plugin_Z_TestA_Ultra.dat

[Ganaram Inukshuk 906]

I've pinned the topic for obvious reasons of visibility and to find any helpers.

[Lucario Boricua 7,050]

For all interested participants who don't know how to edit the Traffic Simulator using the reader programs, message me to prepare a file which combines both the speeds for testing and the capacity setting of your choice. Preparing all the files in one go would be a tedious undertaking, so I'd rather distribute them as they're requested.

[Naomi57 2,985]

Some delicious possibilities there, @Lucario Boricua.  Could a GLR-based cycling network possibly allow RCI access?

I don't have time for testing at the moment, but I did a fair bit of testing for a month near the start of the year, using these settings below.  Very enjoyable to watch the change in walking routes, walking inclination, and mass-transit usage.

On 30/12/2020 at 3:09 AM, Naomi57 said:

https://community.simtropolis.com/forums/topic/760074-how-to-diverge-traffic/?tab=comments#comment-1743714
 
     The new values in pink and blue, the old values highlight straw yellow.

Happy to msg with you about my testing and experiences if you'd like to discuss further.  I've always loved watching traffic routes and traffic volumes, and this change left a big impression on me.

https://en.wikipedia.org/wiki/Life._Be_in_it.

[Lucario Boricua 7,050]

     Glad to see @Naomi57 interested!  Want to sign up formally for this project?

 

Let's get everyone up-to-date with what's been going on with the Traffic Simulator Tuning Experiment:

• I do apologize for my lack of follow-up this first week, things ended up quite complicated this past week and I've barely been able to do SC4 nor NAM team stuff of my own.
   
• There's some preliminary testing I was doing with @Djohaal some weeks ago, which indicates that the pedestrian speed of 20 km/h may actually be too high for streets and pedmalls. The behavior we get from it resembles cycling instead of walking. Sims opt to do full local trips by walking instead of taking transit or driving. It is, however, a good starting speed for a dedicated cycling network.
   
• Last weekend we didsome internal NAM testing with @Tarkus about which networks could be used for a dedicated cycling system and for a draggable pedmall system. Sad to say this, but it won't be based on El-Rail / GLR. Testing indicates that we get the same behavior we once had when we tried to use the conventional rail to do the double decker RHW-4 network, it defaulted to road speeds and capacities. This also means that the street-based override system, with slightly higher ped speeds and/or slightly lower motor vehicle speeds, remains the preferred option for a draggable pedmall system.
   
• On the good news, however, we did realize that there is a suitable network for a cycling override, the Real Highway! It's actually quite convenient, surprisingly enough. The base network repurposed for the RHW, the Dirt Road, does support pedestrian traffic. The RHW, aside from ground-level RHW-2, is designed to only use car paths on its overrides, and as such, it only supports motor vehicles. We could eliminate the L0 RHW-2 pedestrian paths, increase the pedestrian speed on the Dirt Road in the Traffic Simulator, and create an entirely new RHW-based override system for the bicycle network.
   
• I'm sure that we'll get concerns from players who might object to a cycling network which lacks the cosmetic element of cyclist automata. There's actual experience in summoning dedicated automata on modded networks, using LUA scripting. We can make sure that the cycling network uses the exiting pedestrian transit type under the hood, but also make sure that the network's visible automata are cyclists instead of pedestrians.
   
• I've been talking with Brian, a traffic simulator testing veteran in the NAM team, about how to proceed with this project. One thing he does want is to arrange some meetings in which the participants are all at the same place and time, to provide workshops, guidance and testing files more expediently. For that we're able to use the Discord server of SC4 Devotion. For those who aren't there, message me to send you the corresponding invitations.
   
• Another variable we're exploring in this experiment is altering the Trip Starting Cost by Travel Type. This variable adds a time penalty for each transit type when computing the commute times of candidate routes. Under here, we can edit up to 3 values: default, car commute strategy, and transit commute strategy). The benefit of this variable is it can make walking more attractive only at the start of the trip, but it must be tuned carefully, as it's independent of the various transport networks, as opposed to the network-specific speeds. Its effect would instead affect all networks and require more thorough testing to ensure it doesn't break other areas of commute behavior in SimCity 4.

[thecitiescenter 3,059]

On 7/18/2021 at 6:17 PM, Lucario Boricua said:

 

• There's some preliminary testing I was doing with @Djohaal some weeks ago, which indicates that the pedestrian speed of 20 km/h may actually be too high for streets and pedmalls. 

here in the US we use 3.5 ft/sec as average pedestrian walking speed when designing crosswalks and determining amount of Walk time  to allot at a traffic signal so that pedestrians have enough time to safely cross.  The general range goes up to 4.3 ft/sec.  How that translates to game programming I have no idea, but its what we use at work in the real world (Im a Transportation Planner IRL).

This is a cool project btw and thanks for taking it on.  Look fwd to seeing it progress!

[Lucario Boricua 7,050]

6 hours ago, thecitiescenter said:

here in the US we use 3.5 ft/sec as average pedestrian walking speed when designing crosswalks and determining amount of Walk time  to allot at a traffic signal so that pedestrians have enough time to safely cross.  The general range goes up to 4.3 ft/sec.  How that translates to game programming I have no idea, but its what we use at work in the real world (Im a Transportation Planner IRL).

This is a cool project btw and thanks for taking it on.  Look fwd to seeing it progress!

The traffic simulator and the pathfinding heuristic are nowhere near as comprehensive as one might like to simulate real commuting behavior while constrained by the actual physics of movement (ex. set the ped speed to 4 km / h while leaving cars on roads at 50 km/h, and you'll get just about no pedestrians). My goal with these experiments is to find modifications to speeds, time penalties and commute strategies, which result in realistic commute outcomes, even if the underlying numbers do not seem realistic when looked at through the lens of the physics of realistic movement. It also aspires to open up two new networks to provide a genuine multimodal transportation experience, hopefully to ensure the community at large can further customize their cities.

Thanks as well for showing interest in this project! Shouldn't be long until I bring the next updates.

[Leo -- 186]

I would like to try to be a tester but to be honest I don't have any good testing cities at the moment and I can't be bothered to edit the Traffic Simulator (just too lazy)

[Lucario Boricua 7,050]

38 minutes ago, Leo -- said:

I would like to try to be a tester but to be honest I don't have any good testing cities at the moment and I can't be bothered to edit the Traffic Simulator (just too lazy)

PM me with the capacity setting you use and I can send you the edited traffic simulator files. This applies for anyone else who wants to participate and either doesn't know or doesn't want to edit the files themselves. As for testing cities, any regular gameplay city used will do, one of the goals is to get these changes tested out in a variety of play styles, so don't worry about not having suitable cities specific for testing.

[RoddyUK 22]

This is probably not the best place to mention this. If not would you please paste it to the correct group?

 

 The NAM doesn't seem to provide bus only lanes. They're quite common in Europe. Operated by "bus gates" (ie warning signs saying "bus only" signs) they are pretty common. No traffic apart from buses, cyclists and pedestrians are allowed through

I quite like to make car traffic unnatractive to some of my industrial areas - ie public transport only - but I'd also like to be able to solve congestion using the same system to push cars off some of my roads and force traffic on to Avenues or RHW networks.

Otherwise I end up with loads of car traffic grinding through street grids. Which means I get loads of congestion and end up having to convert streets to roads.

And inserting one-way systems becomes silly - because sims can drive so fast along them they become more, rather than less, attractive.

Being able to impose tight speed limits on streets or roads would also help - I mean, every Western city uses that method to stop rat-running, doesn't it?

[Lucario Boricua 7,050]

@RoddyUK You might be at the best place to bring these ideas, actually! One of the main reasons why I'm conducting this project is to explore possible adjustments to the Traffic Simulator, precisely to facilitate some of these changes. Keep in mind that not all of them are feasible in a straightforward manner, as some of them may require modification of the Pathfinding Heuristic (the algorithm controlling traffic in the game, the Traffic Simulator are its editable variables) and the properties of the various networks and travel modes. Changing these three elements are the domain of game engine modding, which requires highly advanced DLL mods working with what effectively is a black box.

My suggestion is to follow this topic, we're gonna be quiet for some more time, but once we get NAM 42 published, I expect to publish some of my initial findings and guide the other participants in the testing of the modified traffic simulator. It's possible that the first round of tweaks we've been trying out could indeed alleviate your concerns about congested local streets and under-utilized arterial and freeway/motorway networks.

[Propfam 2,305]

I'm sorry. I can't play SimCity 4 right now due to

1. My laptop is problematic. The keyboard is erranously active for no reason.
2. More importantly, I've to do some preparation for my life, including some planning about my life. That'll take a huge chunk of my time.

So, I handed out my testing to someone who wants to be volunteers. I'll engage what's happening here from my phone. If you have some questions/idea about SC4 and I can't answer/execute properly, that's why. Thanks.

[Lucario Boricua 7,050]

I'm pleased to announce that I've finally included all the files for Test Battery A of Simulator Z's multimodal modifications! Anyone interested can use these, to install, replace your respective version of NetworkAddonMod_Traffic_Plugin_Z_[capacity].dat file with the one of your choosing.

     I will also say that, after some internal deliberation in the NAM team, that we might be doing far more ambitious traffic simulator experiments. I'll announce the corresponding details when we're ready.