Background:
Interventions involving changes to the built environment that address the environmental conditions underlying low levels of physical activity can result in meaningful population level increases in physical activity. Although utilitarian cycling is related to characteristics of the built environment, limited research has evaluated whether or not built environment interventions can impact utilitarian cycling. BIXI (BIcycle-taXI) is a public bicycle share program first implemented in Montreal, Canada between May 12th 2009 and November 30th 2009 and is an example of a built environment intervention. BIXI increases accessibility to cycling by making available at low cost 5000 bicycles throughout 450 bicycle docking stations located in Montreal’s central and more urbanized neighborhoods.

Objectives:
This study examined the impact of implementing the BIXI public bicycle share program on the likelihood of utilitarian cycling in the population of a large urban area.

Methods:
A pre-test post-test design coupled with spatial mapping of the location of bicycle docking stations was used. Two population-based samples of adults participated in telephone surveys. The sampling plan involved random digit dialing for individuals residing on the Island of Montreal and 25% oversampling of telephone numbers corresponding to residential addresses where BIXI docking stations were implemented. Sampling fractions were 0.001 for both surveys. Pre-implementation data collection occurred between May 4th and June 9th 2009. Post-implementation data collection occurred between October 8th and December 12th 2009. The pre- and post-implementation surveys consisted of 2001 (Mean age=46.2 years, 51.2% female) and 2502 (Mean age=44.4 years, 58.5% female) adults and response rates were 32.6% and 34.6%, respectively. There was minimal overlap between surveys.
The dependent variable was a dichotomous indicator of utilitarian cycling during the previous week. The primary independent variables were survey period and proximity to BIXI docking stations. Control variables included mixed land use, street connectivity, and sociodemographic characteristics. A four step logistic regression was performed on the combined data sets (n=4503): (1) Survey period: a dichotomous variable distinguishing pre- vs. post-implementation surveys; (2) Proximity to BIXI docking stations: an ordinal variable representing distances between home and the nearest BIXI docking station from 1m-1000m, 1001m-5000m, and greater than 5000m, (3) interactions between survey period and proximity to BIXI docking stations; and (4) statistical adjustments for land use, street connectivity age, sex, and education. Post stratification weighting for age and sex was applied to all analyses. Since docking stations were implemented in areas where people were already more likely to perform utilitarian cycling, we hypothesize that significant interactions (step 3) rather than main effects of survey period or proximity to docking stations were evidence that implementation of the BIXI public bicycle share program results in changes in the likelihood of utilitarian cycling.

Results:
Descriptive analyses showed that 8.0% (n=139) and 9.4% (n=186) of respondents had engaged in utilitarian cycling in the pre- and post-implementation survey periods, respectively. In models including all variables, the likelihood of utilitarian cycling was similar across pre to post-implementation periods (OR=0.53, 95% CI: 0.27, 1.03). However, compared to living more than 5000m away from a BIXI docking station, presence of a BIXI docking station within 1000m from home was related to greater likelihood of utilitarian cycling (OR=2.37, 95% CI: 1.45, 3.87), while living between 1001m-5000m was not (OR=1.54, 95% CI: 0.91, 2.59). Interaction terms revealed that in the post implementation survey period, the likelihood of utilitarian cycling for individuals living within 1000m of a BIXI station were 3.22 (95% CI: 1.53, 6.80) while the odds were 2.32 (95% CI: 1.06, 5.09) for individuals residing between 1001-5000m from a BIXI station. Other factors associated with utilitarian cycling were being male (OR=1.69, 95% CI: 1.33, 2.16), aged between 35-44 years (OR=0.62, 95% CI: 0.39, 0.99), 45-54 years (OR=0.51, 95% CI: 0.31, 0.82), 55-64 years (OR=0.32, 95% CI: 0.18, 0.59), 65 years or older (OR=0.17, 95% CI: 0.07, 0.42), having a trade school (OR=2.43, 95% CI: 1.41, 4.18), college (OR=1.84, 95% CI: 1.16, 2.93) or university (OR=2.92, 95% CI: 2.00, 4.25) education, and being on a work leave (OR=0.54, 95% CI: 0.32, 0.92).

Conclusions:
During the first season of BIXI there was no increase in utilitarian cycling in the overall population. This is expected because BIXI was not implemented on the entire Island of Montreal. The interaction between survey period and proximity to BIXI docking stations showed a significantly greater likelihood of utilitarian cycling among individuals living closer to BIXI docking stations in the post-implementation survey period. These findings provide preliminary evidence that implementation of public bicycle share programs can increase the likelihood of utilitarian cycling. Extension through ongoing surveillance and replication in other sites is warranted.

Support:
Research reported in this abstract was supported by Canadian Institutes for Health Research (CIHR) grant for Intervention Research (Healthy Living & Chronic Disease Prevention) and by LG’s CIHR/CRPO (Centre de recherche en prévention de l’obésité) Applied Public Health Chair on Neighborhoods, Lifestyle, and Healthy Body Weights.