Quoted from schudel5:

The 3,000 and 5,000 I think are selectable (along with maybe other values if you wish) using jumper pegs in the backbox. Mine is only set to 3,000 points for another ball.
It is interesting to note, as I thought something was wrong, when you complete the 4 rollovers at the top and get the added ball, only 2 lanes light up again. For the subsequent extra ball, only the two that are lit need to be completed. I thought there was something wrong but learned that's how it was designed.

Quoted from jrpinball:

Yes, this is correct. Same with "Cow-Poke" and "Flipper Cowboy". The two which are lighted and unlighted on the subsequent ball is determined by the state of the alternating relay. This also corresponds with which of the two slingshots is lighted for 10 points. If the lighted slingshot doesn't move on every step of the one point score reel, check to see that the alternating unit coil isn't fried. It's a common issue on "Subway", "Hurdy Gurdy", and a few other games because this coil remains energized even in "game over" state depending on the final position of the one point reel (odd or even number).

As far as a awarding extra free balls, I've seen several "Subway" machines do this, especially when completing the top four rollovers. I had one recently which would award multiple extra balls when hitting the lighted center target. I found a motor switch which was not opening (I believe it was on "C" level of the motor),
and resolved both issues by properly adjusting this switch.
If yours is awarding random free balls, that may be another issue entirely, but note if the subway doors open or not when it gives an unearned free ball. Free balls awarded for meeting a score threshhold do not open the doors. Making the top four rollovers or hitting the lighted center target do open the doors. This may be a clue to resolving the issue.

I would check to see if the slingshots alternate with the one point reel. The lighted lanes shouldn't always be the same two after making the four.
If they don't change, your alternating unit coil is probably bad. It's a common thing on "Subway".

Quoted from pinwiztom:

Does Subway give specials AAB when rolling over the two side lanes when lit, like on CrossTown? I think the game you bought at PPM sale might have been mine that i donated, if it has a repainted generic red white blue CAB?

Quoted from pinwiztom:

Does Subway give specials AAB when rolling over the two side lanes when lit, like on CrossTown? I think the game you bought at PPM sale might have been mine that i donated, if it has a repainted generic red white blue CAB?

Quoted from pinwiztom:

I bought the game many years ago and maybe played one or two games before it went into storage,
so do not recall any mystery free AABs
[quoted image]
Here is the only photo i could find at present time of the Subway i donated to PPM
with its badly painted generic Red/white/blue CAB

Quoted from jrpinball:

"Subway" does not award extra balls for the lighted side lanes. When lit (by making the corresponding top rollover) the score value changes from 10 to 100 points. That's all. It's possible that the person pinwiztom bought the game from in Ohio or another previous owner may have modified it, and Tom didn't notice it because of his limited amount of play on it.