Try this little trick. Accept the ride (that you don’t want) then cancel and choose 'Other" as the reason. But do it as fast as you can.
I read that tip and tried it this past week. I’m pretty sure it worked (at least most of the time as my acceptance rate was 95% highest ever).
This trick also helps you be available for other pings faster since you do it in a few seconds rather than wait 15 seconds.