In addition to reducing congestion, bike-sharing can cause a modest reduction in the demand for parking. A recent working paper on Social Science Research Network (SSRN) by Konstantinos Pelechrinis at University of Pittsburgh and Beibei Li and Sean Qian at Carnegie Mellon University reports that a comparison of parking data and bikeshare data shows a very small reduction of car trips to places where a bike share station is added.
To estimate the effect that bike share had on car trips, the researchers paired Shadyside’s bike dock data with parking meter data from [Shadyside and Squirrel Hill] neighborhoods.
The researchers measured the differences in parking rates in the month before and a month after the bike-share stations were installed in Shadyside (May 2015 and July 2015). The researchers then charted the hourly difference between parking events in Shadyside and Squirrel Hill.
Bike-share trips replaced at most about 69 car trips per day, out of 2,250 daily parking events in the neighborhood of Shadyside. This is a 2 percent decrease in parking demand (adjusted for the lost curb parking space for the installation of the bike docks) after the program’s launch in 2015.
The researchers estimate that level of trip replacement over a month would produce approximately 1,346 fewer car trips, 82.5 fewer gas gallons, 76,470 calories burnt, and 0.73 fewer metric tons of CO2 emissions from trips to Shadyside.
And that's just one neighborhood, for a newly installed system that is much smaller that Capital Bikeshare. CaBi likely is reducing trips by even more. While this seems like a study of something else - parking - than the one reported yesterday, its actually a complementary study. Both show that bikeshare can make a modest change in driving, reducing congestion and improving air quality. It creates a powerful argument for creating bike share systems, expanding them and shows - in part - why subsidizing them makes sense.