You think traffic is bad now!

Good morning, Washington. Nearly two months after Hurricane Irene postponed the celebration, the nation’s first black president will serve as the keynote speaker for today’s official dedication of the Martin Luther King Jr. National Memorial. There’s no rain in sight.

The National Capital Region Transportation Planning Board voted unanimously today to add the Purple Line to its long-range transportation plan, a key approval in the lengthy process to build the new line. Whether the proposed 16-mile line connecting Bethesda to New Carrollton will be light rail or bus rapid transit is still an open question, but a decision on that could happen as early as the end of the summer, assuming the next step, an…