As you might be aware, this website is ran by the volunteers who maintain the navigation map of Waze within Belgium. The Waze app however is maintained solely by Waze, the company. We therefore do not have any control over what gets added to the Waze app.
It is however possible to send in suggestions to Waze! Several years ago, Waze has set up a suggestion box at UserVoice: https://waze.uservoice.com/forums/59223-waze-suggestion-box
It probably comes to no surprise that an app with such a following generates thousands of suggestions. Admittedly, the odds of your suggestion being picked up remains quite slim as long as other people don’t express their support for your idea as well. Still, this suggestion box would be the best way to send in any suggestion you have for the app.
Note: feel free to continue to approach us via social media, our forum or directly on Slack for anything local or anything related to the map. As a community we do have a certain influence on the priorities in Waze. Don’t expect too much either though. We’re a strong community, but obviously we remain a small country.