Here's a median conversion at University of California (Davis). The lawn was converted first to wildflowers but then converted again to a more landscaped native perennial garden. Or perhaps different parts of the median conversion were done with different plants? From the Public Gardens Blog:
The first project is the conversion of the La Rue road median strip from turf to mulch and shrubs. The turf represents a 1950’s-era aesthetic, and requires a high frequency of maintenance (see photo above). The safety of the workers maintaining a turf area in the middle of a busy road is also a concern. The redesigned median will be designed and built by the Campus Planning and Community Resources team, leveraging the strengths of the Arboretum, Putah Creek Riparian Reserve, Grounds, Agricultural Services, and Landscape Services.
The Arboretum will be working with Skip Mezger, Campus Landscape Architect, to design the median using drought-tolerant shrubs and grasses. These plants require lower water use, are more aesthetic than turf, and require less frequency of maintenance. Mulch for the project will be developed by chipping tree branches gathered during routine maintenance on campus, and through removal of eucalyptus trees from along Putah Creek, as part of habitat restoration efforts.
Weed abatement at this site began yesterday and will occur again in 3-4 weeks. So now, when you see brown patches here, you’ll know that’s a good thing! The UC Davis Public Garden team is preparing to convert this site!
Read about the entire project here.
Issues with visibility can be a problem with wildflowers in medians as explained in this post by Dry Stone Garden Blog.