Variable:vehicle flags

From TTWiki

Various flags that define the vehicles behaviour.

Two coupled vehicles face opposite directions (used by all diesel and electrical engines)
Has a driving cab (trains with driving cabs or engines on either side don't turn around at the end of the track, but drive backwards)
Front axis can share bogie (field_24[0] defines shared bogie type)
Rear axis can share bogie (field_24[1] defines shared bogie type)

When Bit 2 and 3 are set, field_24[0] is for front bogie, field_24[2] for rear and field_24[1] is the actual vehicle.

Auto-placing evenly spreads new vehicles along the train, rather than just appending them (used only by TGV and Electra-Star power cars)
Is a power car and explicitly requires a driving cab with Bit_1 set.
land vehicles: Vehicle can not drive backwards (used by all trucks and busses, buggy for trains)
planes: Use slope sprites for taxiing (used by old planes)
land vehicles: Controls the exhaust for an engine on its limit. If not set, the exhaust is continuous, otherwise it's more random (used by all steam engines).
planes: Vehicle is a helicopter
Can it run on any type of track? (used by all buses and trucks)
land vehicles: There can not be more than one of these vehicles on a train (used by all road vehicles)
planes: Use slope sprites for landing (tilted backwards; used only by Concorde)
If the vehicle requires two locomotives (for example, the TGV)
If the news announcement disabled when this vehicle is invented
Can the vehicle use a rack rail?
If the vehicle is refittable(mostly planes and passenger boats) (Refitting allows only mail, food, goods, and grapes. New capacity is passenger capacity divided by 2.5)