Every so often (often around election time), light rail, tram fanatics, and politicians come up with the idea of converting the busways to light rail operation. BrizCommuter has a look at the reality of this move.
In a Courier Mail article in August 2007, it was stated that the Cultural Centre stop handled 179 inbound buses per hour (bph) in the am peak, and the busiest part of the South East Busway handled 294bph. It can only be assumed that in 2010 even more buses are being run on the SE Busway. As far as BrizCommuter is aware, no light rail system can currently handle more than around 40 trains per hour (tph). So assuming each of these 294 buses has a capacity of 65 passengers (which is an underestimate as many buses are higher capacity bendy-buses), then a light rail system running at 40tph would need trams that could carry at least 478 passengers just to match the current capacity of the busway. This would require a tram so long, that it would be the worlds longest tram at around 71m, and would also exceed the length of some busway stations such as Mater Hill.
The cost of converting the busway to light rail would be considerable, and could take funds away from other public transport infrastructure projects such as fixing the under-utilised rail system. Even with the large expenditure, the busway would still be able to handle more passengers with buses than if it was converted to light rail. This does not help the case for light rail conversion!
There have been suggestions of mixed mode operation, where buses and trams would share the same corridor. There are a few locations where this occurs, notably in Seattle. For starters the Downtown Seattle Transit Tunnel runs at a lower capacity than Brisbane's South East Busway. Mixed mode operation would decrease capacity at Cultural Centre, as trams being fixed to a track, cannot manoeuvre around another bus in a similar way that buses can easily manoeuvre around another bus. Anyone who has observed Cultural Centre bus station in operation can see the usefulness of the manoeuvrability of buses. Seattle's system also has issues with bus wing mirror heights, that result in 16kph speed restrictions in the stations. Again, this would further decrease capacity.
Light rail conversion would allow for a very frequent service on the core busway route, but passengers travelling from locations away from the busway would have to change onto a feeder bus service. If this feeder service was no more frequent than the existing one seat journey into the city, then it would be considerably less attractive to passengers due to the additional change and resulting extra journey time.
Given that the Eastern Busway will add even more buses onto the "almost congested" South East Busway, then future busway capacity is a major issue. The latest SEQIPP plan includes the "CBD Bus Infrastructure Capacity Program" between 2011 and 2020, although there seems to be little information of what this project entails. Certainly major changes at the Melbourne Street/Grey Street intersection will be required. Running more buses across the Captain Cook Bridge could be an option, maybe with bus lanes? A bridge paralleling the Victoria Bridge may well be required in the not too distant future to handle more public transport vehicles crossing the river. Whilst busway capacity enhancements are required, and light rail may help some of Brisbane's public transport problems, converting the existing busways to light rail is unlikely to be the answer.