Charting Transport

[post updated 10 April 2010 with new data from Sydney and Perth]

The best source of public transport mode share is from household travel surveys that are conducted in most large Australia cities (some more regularly than others).

This charts shows public transport mode share as a percentage of weekday motorised trips from published survey results and data supplied to me by agencies in different states.

Some of these results are not actually from household travel surveys, but are official estimates (including 2002-2007 and 2009 for Melbourne, and 2001 and 2008 for Perth).

On these figures, Melbourne overtook Sydney in 2008-09 (although the 2008-09 Melbourne is an estimate only). The next household travel survey in Melbourne is underway for 2009-10, which will more comprehensively confirm whether Melbourne has overtaken Sydney.

How reliable is this data?

Given that most household travel surveys interview thousands of households in any one year, the results should be pretty accurate for a high level reported figure such as mode share of trips. Household travel survey techniques have matured over the years, so it is likely they are reasonably reliable (particularly more recent results in larger cities).

However there is no guarantee that the survey and calculation methods employed are equivalent.

The Perth survey data for 2003 to 2006 does not correlate with public transport patronage figures, that show a 12% growth over the same period.

For Brisbane I had to add whole number shares for each mode and divide by the sum of motorised mode shares. So there is some uncertainty about the precise motorised mode share.

The Melbourne official estimates are calculated using VicRoads traffic data, and public transport patronage figures.

These figures represent mode share of trips, regardless of trip lengths. Mode share can also be measured as a percentage of kilometres travelled, or total travel time, both of which have their strengths and weaknesses.

Sources:

Melbourne: Victorian Department of Transport (direct communications), but also available in the Growing Victoria Together Progress Report (page 387), in the 2009-10 Victorian State Budget Papers. Figures until 2001 were from the VATS survey, while the 2008 result is from the VISTA survey.

Sydney Household Travel Survey: Data was supplied by NSW Transport Data Centre by email. Public transport trips are inclusive of trains, buses, ferries, monorail and light rail.

Adelaide Household Travel Survey (AHTS): Adelaide Travel Patterns: an overview (if anyone can tell me about whether more recent surveys have been conducted I would be very appreciative, better still if I can get results data!)

South East Queensland Travel Survey: Brisbane Fast Facts Brochure (unclear dating, but PDF was created in 2006 so I assume the results are for 2003-04. The report does not mention whether these are mode shares for trips or kms, however it seems highly likely they are for trips as the walking mode share was 10% and we know walking trips are generally shorter than motorised trips)

Perth and Regions Travel Survey: Data was supplied by the WA Department of Planning via email. The  2003-2006 results are from PARTS, the 2000 figure is a TravelSmart estimate, and 2001 and 2008 are estimates from unspecified sources.