“Outside of downtown, carts are forming neighborhood-oriented clusters” on vacant parking lots, McInelly points out. “At SERA we have promoted food carts as a low-cost urban design solution” — an interim idea for locations where there is no market for buildings.
This is a similar phenomenon as the weekend farmers market taking over a church parking lot. Potentially, the City could authorize through zoning bylaws, sections of parking areas to be managed under a lease arrangement . The manager could then rent space to vendors, and be responsible for maintaining the cleanliness of the site. Unfortunately, many established businesses see this as a threat to their economic wellbeing, rather than potentially increasing the overall activity in an area. Remember, competition is only a threat if you fail to(a) innovate or (b) offer a quality product at a reasonable price.
Here’s some other links about Portland’s Food Cart scene.