Take a picture (if possible) and submit a report via the city’s Report-a-Problem form: https://www.cityofmadison.com/reportaproblem/bikeway.cfm This is usually a very effective way to have things fixed. If the issue is on the UW campus, email their bike/ped coordinator.
Some things that may help get an issue fixed:
- take a picture that shows the problem (or include a little sketch that helps understand the exact location or problem)
- include sufficient detail in your problem description
- be nice
- follow up if the problem persists (also see below)