Looks like Cap Metro Transit fixed route dispatch is out of the CTECC, which dispatches just about everything for Austin, Travis County, TXDOT, and transit. All of those agencies are on GATRRS, but dispatching on either the LCRA 700 or 900 systems wouldn't be an issue.
I would keep an eye on the GATRRS system. I would assume they can access APD, TCSO, and other agencies, given their decent-sized service area through Travis and Williamson counties. Here in San Antonio, VIA Transit has its own P25 system for operations, but the Transit PD guys are dispatched on the AARRS and have access to all the LE agencies in the county.
