Program: 36713
Project: 36713
Buggy source:
private SignalAspect determineMyAspect(BlockPos otherCoord){
  BlockPos myTrack=trackLocator.getTrackLocation();
  if (myTrack == null)   return SignalAspect.RED;
  BlockPos otherTrack=getOtherTrackLocation(otherCoord);
  if (otherTrack == null)   return SignalAspect.YELLOW;
  TrackScanner.ScanResult scan=getOrCreateTrackScan(otherTrack);
  if (scan == null)   return SignalAspect.RED;
  int y1=scan.minY;
  int y2=scan.maxY + 1;
  int x1=Math.min(myTrack.getX(),otherTrack.getX());
  int z1=Math.min(myTrack.getZ(),otherTrack.getZ());
  int x2=Math.max(myTrack.getX(),otherTrack.getX()) + 1;
  int z2=Math.max(myTrack.getZ(),otherTrack.getZ()) + 1;
  boolean zAxis=Math.abs(myTrack.getX() - otherTrack.getX()) < Math.abs(myTrack.getZ() - otherTrack.getZ());
  int xOffset=otherTrack.getX() > myTrack.getX() ? -3 : 3;
  int zOffset=otherTrack.getZ() > myTrack.getZ() ? -3 : 3;
  List<EntityMinecart> carts=CartToolsAPI.getMinecartsIn(tile.getWorld(),new BlockPos(x1,y1,z1),new BlockPos(x2,y2,z2));
  SignalAspect newAspect=SignalAspect.GREEN;
  for (  EntityMinecart cart : carts) {
    int cartX=MathHelper.floor_double(cart.posX);
    int cartZ=MathHelper.floor_double(cart.posZ);
    if (Math.abs(cart.motionX) < 0.08 && Math.abs(cart.motionZ) < 0.08)     return SignalAspect.RED;
 else     if (zAxis)     if (cartZ > myTrack.getZ() + zOffset && cart.motionZ < 0)     return SignalAspect.RED;
 else     if (cartZ < myTrack.getZ() + zOffset && cart.motionZ > 0)     return SignalAspect.RED;
 else     newAspect=SignalAspect.YELLOW;
 else     if (cartX > myTrack.getX() + xOffset && cart.motionX < 0)     return SignalAspect.RED;
 else     if (cartX < myTrack.getX() + xOffset && cart.motionX > 0)     return SignalAspect.RED;
 else     newAspect=SignalAspect.YELLOW;
  }
  return newAspect;
}

Fixed version (ground truth):
private SignalAspect determineMyAspect(BlockPos otherCoord){
  BlockPos myTrack=trackLocator.getTrackLocation();
  if (myTrack == null)   return SignalAspect.RED;
  BlockPos otherTrack=getOtherTrackLocation(otherCoord);
  if (otherTrack == null)   return SignalAspect.YELLOW;
  TrackScanner.ScanResult scan=getOrCreateTrackScan(otherTrack);
  if (scan == null)   return SignalAspect.RED;
  int y1=scan.minY;
  int y2=scan.maxY + 1;
  int x1=Math.min(myTrack.getX(),otherTrack.getX());
  int z1=Math.min(myTrack.getZ(),otherTrack.getZ());
  int x2=Math.max(myTrack.getX(),otherTrack.getX()) + 1;
  int z2=Math.max(myTrack.getZ(),otherTrack.getZ()) + 1;
  boolean zAxis=Math.abs(myTrack.getX() - otherTrack.getX()) < Math.abs(myTrack.getZ() - otherTrack.getZ());
  int xOffset=otherTrack.getX() > myTrack.getX() ? -3 : 3;
  int zOffset=otherTrack.getZ() > myTrack.getZ() ? -3 : 3;
  List<EntityMinecart> carts=CartToolsAPI.getMinecartsIn(tile.getWorld(),new BlockPos(x1,y1,z1),new BlockPos(x2,y2,z2));
  SignalAspect newAspect=SignalAspect.GREEN;
  for (  EntityMinecart cart : carts) {
    int cartX=MathHelper.floor(cart.posX);
    int cartZ=MathHelper.floor(cart.posZ);
    if (Math.abs(cart.motionX) < 0.08 && Math.abs(cart.motionZ) < 0.08)     return SignalAspect.RED;
 else     if (zAxis)     if (cartZ > myTrack.getZ() + zOffset && cart.motionZ < 0)     return SignalAspect.RED;
 else     if (cartZ < myTrack.getZ() + zOffset && cart.motionZ > 0)     return SignalAspect.RED;
 else     newAspect=SignalAspect.YELLOW;
 else     if (cartX > myTrack.getX() + xOffset && cart.motionX < 0)     return SignalAspect.RED;
 else     if (cartX < myTrack.getX() + xOffset && cart.motionX > 0)     return SignalAspect.RED;
 else     newAspect=SignalAspect.YELLOW;
  }
  return newAspect;
}