Version 2. Updated speed measurement and added skip horn if going very slow through the intersection. This is a visable whistle marker with a horn sequence in AI mode. Long, long, short, extra long. I have added a computational section that adds a delay in the sequencer based on train speed verses speed limit. I have modified the primary script to adjust for train speed not matching speed limit. These distances are based on my configuration. Your actual distances may vary depending on type of computer, speed, etc.