Here, it appears, is the answer to the tram-related issue that I have been encountering... secret release notes!
* Improved prim accounting on parcels ** Counts are correct within 1 frame of the simulator (typically 1/45th of a second) ** The categories for prims on a parcel are: Owner, Group, Other, Selected. The Selected category is new and includes selected objects as well as objects being used as seats (such as vehicles). ** Going over limit with selected objects will not trigger object returns... until they are no longer selected. ** When a parcel owner is over their limit the objects will be returned youngest first in order of Other, Group, Owner. This is NOT new, but mentioned here for completeness.
The bolded section is somewhat inconvenient for the operation of the tram. Let me expound for a moment upon the environment through which it moves. The tram is continually passing through different Parcels of Land, as Caledon is owned by many different people, and the route does not entirely fall along that owned by the State. Many of these Parcels approach their limit for primitives on a regular basis, and it is quite easy for them to near limits even further should someone, say, bring out their latest penny-farthing for the amusement of their companions.
The tram itself is around twenty-five primitives if I am not mistaken, and thus may push the Parcel over said limit. As the youngest and Otherest object, it is therefore in line to be returned first. Prior to this latest change there was a period of grace which allowed the tram to pass through an area, given that it spent little time in a parcel but, it appears, no longer.
Of course when there are folk sitting upon the tram, it is counted as Selected in Mr Andrew Linden's piece above, and thus will not vanish, which is a blessing, as there is nothing more embarrassing for a mechanic than to have one's vehicle disappear from under a passenger, sending them to the ground with an ungainly thump and likely spoiling coat-tails or bustles. However, the tram does run for a considerable time without passengers, and this change in behaviour - which I suspected was the case for a while - means that it is returned to my Inventory fairly frequently.
A visitor would likely not notice this at all in fact, since (as is known by all connoisseurs of Vehicular Automata, or at least those who read this Journal) it is recreated at its source within a mere two minutes or less should it ever vanish. The only sign would be if one were actually waiting for its approach. Imagine, if you will entertain me for a moment, the following situation: a young courting couple - call them Edward and Madeleine - decide to take a day out in Caledon. They have a marvelous time of course, promenading along the boulevards, exchanging delightful witticisms with the residents and other visitors, taking in the bracing sea air. Perhaps Edward treats his love to a gift of a splendid pair of shoes, and she him to a finely-made pearl-handled pistol. Or quite possibly vice versa.
The pair are nearing the end of their stay and, after admiring the fine landscape of Port Caledon, are approaching the Caledon I Telehub when they hear a "ting-ting!" "Surely," advises Edward, "that machine yonder is the famous Caledon Tram, scripted by Ms Ordinal Malaprop and built by Mr Shaunathan Sprocket and Mr Reitsuki Kojima!"
"Oh Edward, how wonderful!" cries Madeleine. "Let's wait here and jump upon it when it crosses the bridge! I do so love a tram ride! And such beautiful and correctly-spelled detail it has!"
With youthful glee the pair wait by the side of the pathway for the tram to arrive. It draws nearer; they crouch, giggling, ready to leap... and with a complete lack of ceremony, the awaited vehicle disappears.
Madeleine stands and pouts. "Oh Edward!" she exclaims. "I was so looking forward to that! It has entirely vanished! What can have happened?" Perhaps a small tear of frustration appears in the corner of one eye.
Edward draws himself up to his full height, incensed that someone has disappointed his paramour. "Dash it!" he swears, throwing his hat to the ground. "This is surely some sort of problem with the scripting. That Malaprop woman is nothing but a fraud! Come, Madeleine, let us visit some other sim where one does not have to deal with things vanishing in front of one's face!" And with that they are off, their opinions of Caledon and your author forever spoiled.
Perhaps later, when Edward is enjoying whisky and cigars at a gentleman's club with his cronies, or Madeleine a shopping expedition with hers (or, again, quite possibly vice versa) they mention to all and sundry how this Ordinal person is surely the least competent inventrix since Mr Benjamin Franklin's little-known cousin Bob, who sought to test the power of kites by flying lightning.
We really cannot have this sort of thing occurring.