Grand Theft Auto: San Andreas/Missions/Snail Trail

General

Picking up the Sniper Rifle triggers the train coming into Cranberry Station. Not picking up the Sniper Rifle doesn't seem to fail the mission, so you can technicially take as long as you want.

After that the mission is mostly timed, but there are some triggers. The following table shows different sections of the mission. The timing starts when you pick up the sniper. Sections enclosed in [ ] refer to the first appearance of the corresponding subtitle. The exact times of course depend on what exactly is used as a reference point, so other tests might have slightly different results if they are not exactly the same.

Section	Fastest	If you don't trigger..	Comment
Picked up Sniper	00:00
	+00:12
Train comes to a stop	00:12
Need to be at Cranberry Station to trigger	+00:00	Fails mission after about 2:00	The train start driving slowly after about 1 minute, then it's another minute until you fail the mission. Also be careful not to be too fast, you need to trigger the train after it came to a stop.
[Reporter entered the train]	00:12
	+03:12		The train always takes the same time, whether you are near it or not. You can however enter the train yourself and skip the trainride altogether. Press "get out" on Market Station to be thrown out of the train before the train stops.
[Train approaching Market Station]	03:24
Need to be near Market Station to trigger	+00:20	Reporter leaves train after 2:19
[Reporter left the train]	03:44
	+00:59		The reporter always takes the same time, whether you are near him or not. Although he may take a bit longer if you are too close and scare him (it seems like he stops a few seconds to look around then).
[Reporter looking for a taxi]	04:43
Need to be near the reporter for him to get into a taxi	+0:13, +0:18 or longer	Fails mission after 1:00	You have to be close enough, so the reporter can find a taxi. If he doesn't, the mission fails. It spawns the taxi on either the northern (13s) or southern (18s) road around the train station. If you weren't in the trigger area by the time the reporter starts searching for a taxi, you are loosing time. See #Taxi Spawn for more information.
[Reporter entered taxi]

When the reporter arrives at the end of the pier, you can shoot him and the one he meets as soon as the subtitle appears that tells you to kill them. Although it might be easier to hit both fast if you wait until they stand closer together. Shoot the reporter (left one) first, because the first shot spooks them and the reporter runs aways, while the guy he meets runs towards CJ and eventuelly starts shooting if he gets closer (which he normally won't though if you snipe them from far away).

Train Skip

You can get on the train when it stops at Cranberry Station (San Fierro) and skip the train ride so almost immediately get to Market Station (Los Santos) where you can get out by jumping out before the train stops. Since you skipped the ride of the train you would usually have to wait for, this saves about 3 minutes, but of course you couldn't get the helicopter, so you'll have to find a fast vehicle for the drive back while following the repoter in the taxi. Even considering the slower drive back (e.g. Police Bike about 30s slower than Maverick), this saves a lot of time.

Taxi Spawn

Once the Reporter stops at the sidewalk (The reporter is on the sidewalk looking for a cab.), the taxi can spawn, but only if you are also in the trigger zone (which is a cube around Market Station with a limited height). The reporter doesn't take a random taxi off the street, but instead there can be two places where one will spawn for him, north of Market Station or south of Market Station. From the spawn (The reporter is on the sidewalk looking for a cab.) to the reporter getting in (The reporter has climbed into a cab.) the northern spawn takes 13s and the southern spawn takes 18s (because the drive is a bit longer). The taxi might be obstructed a bit by traffic, but it usually shouldn't be in this part.

The taxi will always spawn on the southern spawn, unless you are in the trigger that makes it spawn in the north. This trigger is placed on the road south of Market Station, but is only a few metres of height (standing on a tall car will already not trigger it it).

Taxi Route

Once the reporter got into the taxi, it starts driving one of three routes, which seem to be randomly chosen (based on experimentation and some random number generation in the script in the area that seems to be responsible for the route selection). The taxi driver AI follows a few set checkpoints, which forces him on the set routes. The routes seem to be kind of the same length, the biggest time differences come from traffic light RNG (and some small difference also attribute to traffic).

Driving Behaviour

The taxi driver always seems to try to swerve around traffic (unlike random traffic, which does not always do that), but always stops at red traffic lights up to the first checkpoint, most of the time stops at red traffic lights up to the second checkpoint and apparently never stops at red traffic lights beyond that. Trying to scare the taxi driver (like hovering over it with a helicopter or ramming into the car) doesn't seem to change anything, even though he sometimes seems to drive like scared, he always behaves that way and also doesn't behave like a regular scared AI (which drives much faster).

The code that makes the taxi drive to the next checkpoint suggests that there may be different factors for running red lights (the number of passed checkpoints, threatening him, RNG), but it is not quite clear how the code works. It also seems like the speed of the taxi is defined in the script, but how that works is not quite clear as well.

Pier Triggers

There are also two triggers at the top of the Pier (at which end the target of the taxi is located), one setting the player as "being on the Pier" the other one as "having left the Pier". If you enter the Pier before the taxi (and stay there), then the taxi will turn around and drive another round. If you drive onto the Pier before the taxi and leave it via another way than the trigger, then the taxi will never enter the Pier unless you enter the trigger again.

This should usually not be a problem in a speedrun, since you will just follow the taxi, but it is interesting to know to avoid, just in case.

Links

• Forum: This and following posts include some tests of Snail Trail
• Forum: Train Skip
• Video: Comparison between using a Helicopter to scare the taxi and a Car (also demonstrating avoiding the trigger, to spawn it south and watching the taxi spawn)