Yes, you need to set up a new AI list, consisting of just the D92 (or whatever bus you which).
Open the AIlist.cfg for your new map.
You should have something like this;
[ailist]
0
-1
23
vehicles\MAN_SD200\MAN_SD77.bus
vehicles\MAN_SD200\MAN_SD80.bus
vehicles\MAN_SD200\MAN_SD81.bus
vehicles\MAN_SD200\MAN_SD82.bus
vehicles\MAN_SD200\MAN_SD83.bus
vehicles\MAN_SD200\MAN_SD83_RLB.bus
vehicles\MAN_SD200\MAN_SD84.bus
vehicles\MAN_SD200\MAN_SD85.bus
vehicles\MAN_SD202\MAN_D86.bus
vehicles\MAN_SD202\MAN_D87.bus
vehicles\MAN_SD202\MAN_D88.bus
vehicles\MAN_SD202\MAN_D92.bus
vehicles\MAN_F90\AI_MAN_F90_Wechselbruecke.bus
vehicles\MB_W123_230E\AI_mb_w123_230e_cab.bus
vehicles\VW_Golf_2\AI_VW_Golf_2.bus
vehicles\VW_Golf_2\AI_VW_Golf_2.bus
vehicles\VW_Golf_2\AI_VW_Golf_2.bus
vehicles\MB_W123_230E\AI_mb_w123_230e.bus
vehicles\MB_W123_230E\AI_mb_w123_230e.bus
vehicles\MB_W123_230E\AI_mb_w123_230e.bus
vehicles\VW_T3\VW_T3_Van.ovh
vehicles\Opel_Manta_B\ai_opel_manta_b.ovh
vehicles\Citr_BX\BX.ovh
[aigroup]
Busses
12
0
1
2
3
4
5
6
7
8
9
10
11
your depot name, or spandau etcSo that text above is the default AI list that puts every bus out on your route.
Now, you need to add a new AI list for just the D92, which is this (make sure you put your own text where the 'italics' are!;[aigroup]
Name of your new AI list here (ie... D92_only)
1
11
your depot name, or spandau etc here(The '1' in the above entry relates to their only being 1 vehicle in the list. The '11' in the above relates to the D92). Now when you're setting your timetable up for your new route, it asks you which AI List you want to use. There's a drop down list, and once you do the steps above, you will have a new entry.... in this case 'D92'.
Cheers,
David