Brisbane has 27 stations with a 4 trains per hour (tph) weekday daytime off-peak service - Central to Northgate, Darra, and Park Road, as well as Coopers Plains, Loganlea, and Beenleigh. All of these locations are serviced by two or more rail lines. Unlike all rail lines in Perth, and many rail lines in Melbourne, and Sydney, no single rail line in Brisbane has better than a 30 minute / 2tph weekday daytime off-peak service.
What about Adelaide? Well for starters, the Glenelg Tram (which has a considerable portion of running in it's own right of way) has 29 stations with a 4tph off-peak service. The 42km Gawler Line (which is a similar ballpark in length to the Ipswich, Caboolture, Cleveland, and Beenleigh Lines) runs a 2 pattern express service to speed up journey times. 7 major stations along the Gawler Line are served by both service patterns, and thus have a 4tph service. With the Gawler Line being electrified, further service improvements are planned in the next few years.
Adelaide's 30km Noarlunga Line currently runs a 2 pattern service which has extra trains before 11am and 2pm. In this period 8 stations receive a 4tph or better service. Between 11am and 2pm just 3 stations have a 4tph or better service, shared with Brighton starting/terminating services, and Tonsley Line services. The Noarlunga Line is currently being extended to Seaford (36km total length) with an opening planned for late 2013. It has been stated that a 4tph / 15 minute off-peak service will then be run on this line, serving all 17 stations between Seaford and Woodlands Park. So unlike Brisbane when huge sums of money are spent on rail infrastructure (Richlands Line and Ferny Grove Line duplication) with only a 30 minute frequency, Adelaide actually plans to considerably improve train services on it's new infrastructure. It should be noted that Brisbane's population is also nearly double that of Adelaide's.
If (as expected) no 15 minute off-peak services materialise in QR's 2012 phase 2 timetables, then within a year, Brisbane will have the worst weekday daytime off-peak train service of all mainland Australian state capitals! The Queensland Government, TransLink, and QR should be very embarrassed that Adelaide will have a 4tph / 15 minute off-peak peak service to many stations up to the 30-40km range from the CBD, whilst Brisbane can only provide a 2tph / 30 minute off-peak service at stations beyond the 16km range from the CBD (with the exception of an irregular 4tph service at Loganlea and Beenleigh).
Interestingly, Adelaide's rail system does not have guards. As with Melbourne and Perth's railway systems which both have half-decent service frequencies, the lack of guards is a much more cost efficient use of staff. Unfortunately QR's culture still appears to be clinging onto guards. SE Queensland's train system urgency needs frequency, not inefficiency!