I’ve been calling the cops at 110 quite a bit lately, reporting cars and scooters that are illegally parked on the sidewalk or along a red line. I don’t report every illegally parked vehicle, but only those that get in my way - on a sidewalk I have to walk past, in front of my front door, at a corner where the traffic is particularly tight, etc. The police usually show up within 20 minutes to issue the ticket. I’ve been doing enough that certain places that used to have a thick lineup of scooters - such as the corner in front of the original Kanpai - are now mostly clear without me having to report anything.
So if you find yourself climbing over some scooters, or find a neighborhood car a particular eyesore, don’t hesitate to call 110!
Another option is a take a photo or video and report it to the police website. But this is better for moving violations as it’s more of a hassle to fill out the form:
New Taipei: https://tvrs.ntpd.gov.tw