You are missing all shape files (and the related .sd files) of the carspawner vehicles (if you had even only one, you wouldn't have got the crash....).
Here the relevant warning strings from your log file:
Warning: Non-existent shape file c:\MSTS\ROUTES\Marias31\shapes\car1.s referenced in c:\MSTS\ROUTES\Marias31\carspawn.dat:line 4
Warning: Non-existent shape file c:\MSTS\ROUTES\Marias31\shapes\car2.s referenced in c:\MSTS\ROUTES\Marias31\carspawn.dat:line 5
Warning: Non-existent shape file c:\MSTS\ROUTES\Marias31\shapes\car4.s referenced in c:\MSTS\ROUTES\Marias31\carspawn.dat:line 6
Warning: Non-existent shape file c:\MSTS\ROUTES\Marias31\shapes\policePHIL.S referenced in c:\MSTS\ROUTES\Marias31\carspawn.dat:line 7
Warning: Non-existent shape file c:\MSTS\ROUTES\Marias31\shapes\truck1.s referenced in c:\MSTS\ROUTES\Marias31\carspawn.dat:line 8
Warning: Non-existent shape file c:\MSTS\ROUTES\Marias31\shapes\van_1.s referenced in c:\MSTS\ROUTES\Marias31\carspawn.dat:line 9
Warning: Non-existent shape file c:\MSTS\ROUTES\Marias31\shapes\US2Pickup.s referenced in c:\MSTS\ROUTES\Marias31\carspawn.dat:line 10
Warning: Non-existent shape file c:\MSTS\ROUTES\Marias31\shapes\car1.s referenced in c:\MSTS\ROUTES\Marias31\carspawn.dat:line 11
Warning: Non-existent shape file c:\MSTS\ROUTES\Marias31\shapes\car4.s referenced in c:\MSTS\ROUTES\Marias31\carspawn.dat:line 12
There are also many other shape files missing in your installation: you can recognize them from log lines like following one
Warning: w-012579+014765.w scenery object 3007 with StaticFlags 00000000 references non-existent c:\MSTS\ROUTES\Marias31\Shapes\US2Lodge1.s
,
so I assume something has gone wrong in your installation. Most probably you did not execute a .bat file copying objects from the six standard routes, or the six standard routes are not present in the MSTS installation where you installed your route.