It's long been an aspiration for the hourly Bristol - Gloucester service with alternate trains extended to Worcester (and Malvern) to be extended every hour, and perhaps that's an idea who's time has come. With the Cardiff - Nottingham train providing an hourly Gloucester to Worcester(shire) service as well, perhaps that's your twice an hour - especially if the connection into the city is good from Parkway. North of Bristol Parkway to Yate - perhaps a second service in the hour would be coming and is Gloucester the place to take and turn it