Past signal at danger.......

I'm sure you've all seen this message pop up. An AI driver passes a signal at danger and waits two minutes before continuing their schedule. There's a spot on my Windweather Tramway where this seems to regularly happen. It's on a tight curve with a speed restriction of 15 mph and a home signal is placed towards the end of the curve. And constantly AI drivers run past the signal.
The ruling speed limit on the tramway is 25 mph and in many places the speed limit is a lot less. The speed limit ahead of the curve is 20 mph and the 15 mph restriction is placed well before the curve itself. I really don't know what to make of this and any advice would be gratefully received.

Place more signals (or invisible signals) in the previous block prior to the SPAD signal

Thanks for your reply. I had a feeling that it might be a signalling placement issue, though this is happening close to the harbour on the tramway where the signalling blocks are short and the speed limits are restricted so it just seems plain strange that the AI driver is running past the signal.
Mind you it was that scruffy lad Christian that was consistently doing this; - I should get Charlie on the job, - he never makes mistakes.

What's the acceleration/deceleration like on the affected vehicles (trams)?

Shane

All the engines that work on the Windweather Tramway whether they are steam tram engines or conventional steam engines are speed limited by their engine specs and in most cases the maximum speed is only around 25-30 mph. The engine that prompted me to start this thread is an 1860s Hicks 0-6-0 tender engine with maximum speed of 30mph and its tender has a working brake script. It was hauling 220 tons of coal in loose coupled unfitted wagons (no continuous brake) and the two brake vans coupled to either end of the train had functional 4 wheel brake van scripts. The speed restriction on the curve was 15 mph. It really should have been able to stop before the signal.

I have found that sometimes having too many signals and speed limit signs close together will cause problem. The problem has to do with the AI logic. The AI 'see' each track section as a block that starts and stops at junctions. If each section has a new speed limit sign, the AI will readjust again for that section even if it's the same speed instead of seeing this as a continuation of the previous speed limit. If you do have multiple 10 mph speed limit signs within this area, remove a good number of them because they are redundant since the AI will be running on the previous speed limit.

Junctions too as I mentioned play a big part in this too in addition to dividing the blocks. Ensure that all intervening junctions are set for the main track rather than left as they are facing sidings, and other lines. As the AI are move along, they will have to stop and adjust a junction, and in particular if the junctions are very close with close signaling, this will cause the AI to SPAD because they start to pick up speed and then have to stop suddenly again. By setting the main line to be unimpeded, the AI will move along slowly without running a red.

Thanks for your advice John. I'm reasonably certain that I have all the points set for the main route through the harbour area so I can tick that one off the list. I will check the placement of the speed limit signs as well just to be certain that they aren't confusing things either. It is quite a tricky little section of my layout with a good few tight curves as well as various junctions leading off to sidings around the harbour and with a swing bridge in amongst it as well.. The solution might be to have one overall low speed restriction on this section rather than the present situation where the speed is dropped from 20 mph to 15 mph or 10 mph and then raised back to 20 mph again.

KotangaGirl said:

Thanks for your advice John. I'm reasonably certain that I have all the points set for the main route through the harbour area so I can tick that one off the list. I will check the placement of the speed limit signs as well just to be certain that they aren't confusing things either. It is quite a tricky little section of my layout with a good few tight curves as well as various junctions leading off to sidings around the harbour and with a swing bridge in amongst it as well.. The solution might be to have one overall low speed restriction on this section rather than the present situation where the speed is dropped from 20 mph to 15 mph or 10 mph and then raised back to 20 mph again.

Click to expand...

I think you're zeroing right in on the spot. Jumping from 5 to 10 to 20 will make the AI see the new speed and readjust causing them to SPAD. I had a similar place on an old route and my solution is exactly what you are aiming for. I made the complex area all 10 mph. Problem solved no more speed-stops, hiccups, and complaints.