Function move_trains_with_velocity 

pub fn move_trains_with_velocity(
    cmd: Commands<'_, '_>,
    q_trains: Query<'_, '_, (Entity, &Train, &Velocity)>,
    q_carriages: Query<'_, '_, &Carriage>,
    q_bogies: Query<'_, '_, &mut TrackPos>,
    q_segments: Query<'_, '_, &TrackSegment>,
    time: Res<'_, Time>,
)

System that moves carriage’s bogies with respect to the carriage velocity