Mode switching studies
1. Capital Bikeshare: http://capitalbikeshare.com/assets/pdf/Capital%20Bikeshare-SurveyReport-Final.pdf
“Bikeshare members substantially reduced their use of car – Four in ten (41%) survey respondents drove a car less often; no respondents increased use of car. More than nine in ten respondents who reduced driving indicated that Capital Bikeshare had been a factor contributing to the reduction.”
Press release version: http://www.capitalbikeshare.com/news/2012/06/18/new-survey-finds-capital-bikeshare-members-drive-less-and-save-big
2. Modeshift is often part of the criteria for Congestion Mitigation and Air Quality Improvement Program (CMAQ) projects.
A. FHWA reviewed and published the results of four bicycling and walking projects.
http://www.fhwa.dot.gov/environment/air_quality/cmaq/research/safetea-lu_phase_1/appendix_c/bicycle_pedestrian.cfm
I find their assumptions (and resulting emission-reduction findings) to be conservative. For example, in the first example, they only count VMT change for the part of the trip that takes place on the facility and they assume that the bike rider uses just half of the 8.3 mile facility. The actual total bike trip converts more miles than get counted in their formula (you have to bike to the trail, right?) and they don’t take into account the new bike commuters attracted to a more complete network (network effects). But I suppose it
being conservative lends credibility among more skeptical audiences.
B. The California Air Resources Board (CARB) methodology for calculating cost effectiveness of air quality projects, which usually includes a mode shift
component, seems to be respected (it’s old and doesn’t calculate PM2.5 emissions): http://www.arb.ca.gov/planning/tsaq/eval/mv_fees_cost-effectiveness_methods_may05.doc (starting on page 29).
3. A few studies:
a. Promoting walking and cycling as an alternative to using cars: systematic review: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC520994/
b. The relative
influence of urban form on a child’s travel mode to school: http://www.sciencedirect.com/science/article/pii/S0965856406000620
Best,
Darren Flusche
Policy Director
League of American Bicyclists
On the Alliance for Biking & Walking: People Discussion Group Update: And some more info posted to the list serve:
We went through some calculations of that sort for this project:
http://www.marc.org/Recovery/assets/tiger/APPENDIX_D_Bicycle_Pedestrian.pdf
I don't know if the studies we were able to find used exactly the type of methodology you are looking for but we came up with some ways of calculating those figures and the associated cost-benefit ratios that I was pretty happy with at the time.
Unfortunately it has been so long since working on that I can't remember the exact details. Anyone else working through the figures and the references given in the link above could probably figure out the sources about as quickly as I could at this point!
But some of the most useful research/studies we used in putting together those estimates are listed below:
* Advocacy Advance Team's summary of research with references:
http://www.bikeleague.org/resources/reports/report_economics.php
* Probably the most comprehensive/exhaustive single resource on the issue of calculating the cost/benefits of investments in bicycle facilities. If there is a study that does exactly what you are asking for it is probably listed here:
http://onlinepubs.trb.org/Onlinepubs/nchrp/nchrp_rpt_552.pdf
* Quantifying the benefits of nonmotorized transportation:
http://www.vtpi.org/nmt-tdm.pdf
* Others:
http://nexus.umn.edu/Papers/TrailsLanesOrTraffic.pdf
Update #2:
Check out the very impressive mode shift numbers achieved in Bellingham, WA, through an outreach program that targeted people based on their expressed interest and provided individualized information on how to bike, walk, or take transit: https://www.whatcomsmarttrips.org/news/mobility_report
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