Traffic AI Police chases not working in v0.18.4

Donj · Dec 22, 2019

Hey guys I have been playing around with the traffic in v0.18.4. I have heard/seen that if you use an official unmodded police vehicle some of the AI will drive illegally and you can chase them and after a while pull them over. I have been playing using an official police car and i can not find any people that are erratically driving and won't pull over. I have seen people on the wrong side of the road, running red lights and stop signs but when i put my sirens on they pull over immediately. Its very annoying as I want to chase some AI without using the flee function. I think something is broken as I have searched for hours and tried everything. Any ideas?

Inertia · Dec 22, 2019

The traffic AI is weird I will agree, I actually much prefferred the behaviours of the standalone mod (but the game implementation is much more convenient). In the standalone mod cars would pull over straight away or flee, however in the game version they wait for your car to slow down then they stop. Not only that but they stop right in the middle of the road, and oncoming traffic has no idea what to do either (see attached pic). Even worse is the police chase logic, they have no game at all and are extremely timid while chasing, making it impossible to get caught unless you hit one of the police cars that spawn and immediately do a 3 point turn in the middle of the road. I'd rather the AI's behaviour go back to the way the standalone mod was, because currently there isn't much point in the traffic unless you want cars to overtake on the highway.

EruptionTyphlosion · Dec 22, 2019

EruptionTyphlosion said: ↑

That's because the BeamNG police AI still isn't programmed correctly.

Rant time here, bear with me. I've been holding it off because I assumed these issues would be fixed in 0.18, but they don't seem to have been. These are my findings after doing a lot of experimentation with the police AI code back in 0.17, and none of these issues have been fixed in 0.18.

Higher risk values increase AI stupidity. BeamNG's police AI is currently designed to increase risk at higher "Heat" levels, which just makes them better at crashing into every single thing they shouldn't. I have done tests with modified Police logic and they are far better at pursuing at the 0.3 risk level (And yes, they will still ram you when needed, but they hit trees, cars, each other, and literally everything else far less often). Police AI risk needs to be set to 0.3 across the board (every heat level), no exceptions.

Another issue is the fact that BeamNG's police AI is set to pursue at a speed LIMIT of 100 mph. This means that the absolute maximum speed an AI cop can go is 100 mph at most, but usually they won't go anywhere near that. The AI needs to use a SET speed rather than a LIMIT speed. This makes the AI know that it must be going that speed, and thus they drive significantly faster to try to get to that speed as fast as reasonably possible. Next, two factors need to be taken into account for determining what speed each individual police car should be set to, suspect (player) speed and the speed limit for the road. If a police car is further away from the player (ie: catching up), then their speed should be SET and constantly updated to the safe speed for the road plus a heat level dependent amount (1 - 10 MPH, 2 - 25 MPH, 3 - 55 MPH, these numbers aren't arbitrary, these are the numbers that work best). When close to the player, their speed should yet again be SET and constantly updated, but this time to the player's speed plus a different amount (1 - 0 MPH, 2 - 15 MPH, 3 - 40 MPH) (this is to prevent large speed differentials causing the police AI to ram cars when they shouldn't be, for example at the Heat 1 "traffic stop" level and ramming slower cars at stupidly high speeds). Also, if a cop detects that it has passed you, then it will try to slow down rapidly in an attempt to take you down by brake checking you, and if that fails it can get behind you again.

There are still a number of critical errors regarding AI police spawning in pursuit mode. First and foremost, when the player has a heat level the police AI should not spawn coming at the player head on, which results in them acting like a NFS Most Wanted Rhino. No police force does that, it's annoying and unrealistic. Secondly, the second the player gets within range of a police car traveling in the same direction as the player, the cop jumps straight into chase mode. This means that the cop car detects the player behind them and so it determines that it must do a U turn in order to reach their target, which either results in the cop car driving backwards into something/off a cliff, or getting stuck in a 50 point turn which means that by the time they are finally turned around, the player is long gone. There are two solutions here. The first option is to make it so that AI cops continue patrolling and don't enter chase mode until the player has passed them, or the second option being that the AI police use the function that lets them spawn parked on the side of the road (not sure if that's enabled yet but that's definitely there), and then turn on their lights and chase once the player has passed them. A combination of the two would be ideal. And if the speed and risk is properly set up as mentioned in steps one and two, then trust me, they're gonna catch up, fast.

The police spawning system during a pursuit has another major issue. Losing them is difficult, not because the cops are competent (they're probably stuck in the nearest tree with the current police logic), but because the second you lose one the next one spawns directly in front of you. It's like how GTA V's police operate, and the only way to evade them consistently is to drive off road as far as possible, which is only possible with certain cars in certain areas of certain maps. First and foremost, police reinforcements should not spawn on dirt roads. They should be able to chase you onto dirt roads, but they shouldn't spawn there. If the player gets out of range of police units for a certain amount of time (relatively short), the police should enter a "search mode" where they kill their sirens, activate high beams at night (which would activate spotlights on the cops cars that have them), enter "random" mode at patrol speed (rather than automatically homing in on the player like they currently do, which is cheating) and only reengage when they are much closer to the player than their normal pursuit range, alongside longer respawn times during this "search mode" to prevent the existing issues with them constantly spawning on top of the player whenever you lose them. After another longer period of time, you "have evaded the police".

Another thing is that is a police vehicle is severely damaged, it should stop trying to chase you. A completely destroyed wreck of a cop car inching forwards at 2 mph is immersion breaking. Just turn the lights and engine off, set the AI to "Stopping" and remove it's ability to bust people.

More of an AI thing, but the AI needs to apply the brakes whenever it starts to fishtail. This is the one issue with high speed set cops.

I've made experimental versions of the 0.17 traffic scripts adding some of these features (which don't work anymore for obvious reasons), and the difference is night and day. If all these tweaks are made, trust me, the police will go from completely useless to a force to be reckoned with. These changes shouldn't take much time to implement either.
--- Post updated ---
EDIT: Made a few minor updates to the post.
Click to expand...

Putting this here because the whole police AI system doesn't work even remotely correctly.

Donj · Dec 22, 2019

Yeah, I hope they fix it soon. As I've seen videos and the AI that don't pull over are seemingly easy to find where in game they are not. Although the videos were from like october so something is broken.

Nadeox1 · Dec 22, 2019

Thanks for the report.
Chase Mode has not been in our focus for the past few updates, and it appears that something is quite off with it.
We have already took note and will be checking this.

Rz1 · Feb 8, 2021

I am encountering the same issue now. There are no erratically driving cars to stop. I have tried erasing cache, changing cars and maps but nothing. Help?

Great Wolf · Jun 30, 2021

I encountered the same thing as it seems it wont register certain police vehicles as an "AI police". Example of this would be the oldsmobile police vehicles. they act as normal civilian cars instead of police which is annoying as I wanted to make a 1988 scenario. if there is any way I can edit and mark the vehicle as a police vehicle please let me know.

Agent_Y · Jun 30, 2021

Great Wolf said: ↑

I encountered the same thing as it seems it wont register certain police vehicles as an "AI police". Example of this would be the oldsmobile police vehicles. they act as normal civilian cars instead of police which is annoying as I wanted to make a 1988 scenario. if there is any way I can edit and mark the vehicle as a police vehicle please let me know.
Click to expand...

The Oldsmobile mod for some reason doesn't work with AI very well. And I can't tell what exactly is wrong, the mod is massive and trying to find the one thing in it that breaks AI would take so much time. The only thing I can think of is to turn on the sirens manually and set all AI to chase you.

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