I'm using convoy spacing with buses. It's difficult. It works most of the time, but sometimes a bus arrives only one minute late, ¡¡only one minute!!, and it must wait the whole slot time, causing an important delay in the whole line. This topic is commented in this thread:
https://forum.simutrans.com/index.php/topic,17148.msg163289.html#msg163289You can reduce the probability of a bus arriving late by setting the frecuency a little higher, reducing a few buses per month. But with this you are causing the buses waiting unnecesarily, only to prevent an occasional bus arriving late.
I have a suggestion to make the convoy spacing more simple: instead of the current setting indicating convoys per month, I suggest to put only a setting indicating how many minutes you want your convoys separated, normally the calculated frecuency (average trip time / number of convoys).
I think it can be done with a variable in the bus/train stop, to store the time at which the last convoy leave the stop. For example, a convoy leaves the stop at time 46:35. The separation is configured at 15 minutes. Then arrives a convoy at 1:00:00, it must wait 1 minute and 35 seconds until 1:01:35.
With this system, if a convoy arrives late it doesn't wait, it departs inmediately. But it stores the departure time in the variable I've suggested, causing a delay to the rest of the line. For example, if a bus arrives 1 minute late, it causes 1 minute delay to the rest of the line, but only one minute and not 15 minutes.
I think my suggestion can work and it is more simple and more intuitive. With all my respect to the coding of the current spacing system, but in computer engineering, and in engineering in general, more simple is better.
Thank you!!