The current urban transport infrastructure forms part of the obesogenic environment in Australian cities. In advocating increased spending on active transport infrastructure, evidence for its effectiveness is needed. We used a ‘natural experiment’, the strongest research design that is feasible in practice, to examine the effect of a bridge on the cycling behaviour of commuters to a university campus.
The Eleanor Schonell (‘Green’) Bridge is the first bridge in Australia exclusively designed for buses, cyclists and pedestrians. It connects the University of Queensland (UQ) St Lucia campus, located on the left bank of Brisbane river, with suburbs on the right bank. We used data from an online questionnaire survey, implemented before (2006) and after (2007) the completion of the Green Bridge to assess travel patterns of students and staff to and from the campus. We estimated the change in the proportion of commuters that travel to UQ St Lucia by bike, comparing the change over 2006 (no bridge) to 2007 (with bridge), comparing those living on the right bank (who could use the bridge in 2007) with those living on the left bank (for whom the bridge made no difference).
We found an increase in cycling on both banks, with the share of ‘bicycle only’ rising from 2.2% to 5.4% on the right bank and from 3.3% to 5.5% on the left bank. The relative probability of cycling (with 95% confidence interval) in 2007 compared to 2006 for the right and left banks were 2.50 (1.85 – 3.37) and 1.63 (1.31 – 2.04) respectively. The overall ratio of change of right over left bank was 1.53 (1.03 – 2.20), implying that the Green Bridge may have increased the proportion of cycling to work by 53%.
Well-connected bikeways can increase cycling for transport.