Vitruvian Park / Vitruvian West (no relation to Viridian in Arlington) is a walkable mixed-use masterplanned district that is still not served by DART bus routes; the route 488 bus stop at Valley View & Marsh is three quarters of a mile walk away. Route 488 then serves Brookhaven College while linking Farmers Branch Station with Addison Transit Center. From there this route heads down to Forest Lane and proceeds east (including the light rail station on Forest Lane) all the way to LBJ/Skillman Station on the Blue Line.
When Addison Transit Center gains Silver Line / Cotton Belt rail service, then it will be connected to the Green Line rail at the very next Green Line station and the 488 connector may be worth revising altogether.
I could see a high frequency BRT (Bus Rapid Transit) express line being successful from 1. LBJ/Skillman to 2. LBJ/Central to 3. Midtown to 4. Addison Circle / Transit Center, 5. Vitruvian, and 6. Farmers Branch Station, no longer keeping any other stops in between.
DART's local bus services could be designed to provide the most convenient coverage off of this backbone.