Thomas Street is one of several streets that will be reconnected between South Lake Union and Uptown when the North Portal of the waterfront tunnel is completed. This will create important new pedestrian connections. In 2011, DPD and neighborhood stakeholder drafted this streetscape concept plan to guide future streetscape improvement on Thomas St. Although final traffic configurations were not finalized at the time, this urban design plan remains a general guide to the preferred character and design intent of the future Thomas St. streetscape. 

Streetscape concept plans can be implemented over time through improvements with private development, or through City capital projects. A key feature of the Thomas St. Streetscape Concept Plan is that it anticipates changes that will occur in conjunction with planned revisions to Aurora Ave. N. and SR 99. The concept plan builds on other recent planning work for South Lake Union including the South Lake Union Urban Design Framework.

Much of Thomas St. is designated as a Neighborhood Green Street. Green Streets designations are a way to achieve particularly excellent pedestrian corridors. Green Streets add to livability of a neighborhood, link public open spaces, and can include green stormwater infrastructure. The streetscape concept plan explores design options to integrate these types of Green Street features on Thomas St.