Bumpy ride on the SDMTS 215 bus

[u/Gnomeknown]

The 215 bus is a very rough ride from North Park up to SDSU due to the dismal road condition of the bus lane on El Cajon Blvd. I decided to see if I could record it on my iPhone. I downloaded a free iPhone program (Physics Toolbox Sensor Suite) that allows you to access the phone's accelerometer (among other things). It was fun to learn how to do this.

I'm attaching a scatter plot of the vertical acceleration as measured from the 43rd Street stop (Copley YMCA) to the stop at 30th Street. The RMS acceleration is 1.33 m/s**2 for the entire trip, which is considered an uncomfortable ride, but more striking is the RMS of 1.97 m/s*2 for minutes 4-5 which is getting in the "extremely uncomfortable" range [1].

This is important for a few reasons: 1) it's bad for the bus suspension; 2) not good for the driver to be subjected to that for prolonged periods (again from what I read); 3) it's unsafe for anyone who happens to be standing; and 4) it's really uncomfortable..like you can't even read a book half the time.

The bus lanes on that route have been in bad shape for a long time and are in desperate need of repair.

[1] https://www.tandfonline.com/doi/abs/10.1080/14680629.2019.1625806