Photo by Megara Tegal on Flickr.

Add your voice to the public involvement process, learn about the history of a DC landmark, and meet fellow transit supporters in Montgomery County at events around the region.

Whose voices do planners hear?: Social media and evolving technologies have allowed a more diverse set of voices to weigh in on the planning process than ever before, but informal comments online often aren’t formally recognized by planning agencies. How can planners bridge this communication gap?

The National Capital Planning Commission will host a panel discussion on this issue on Wednesday, April 9, 7-8:30 pm. NCPC’s William Herbig will moderate a conversation with David Alpert of Greater Greater Washington, Cheryl Cort from the Coalition for Smarter Growth, Don Edwards from Justice and Sustainability Associates, and NBC4 reporter Tom Sherwood. The free event is at NCPC’s offices, 401 9th Street, NW, Suite 500. RSVP here.

After the jump: learn about the history of the Washington Coliseum, attend a community drop-in workshop about the Maryland Avenue SW transportation study, and attend a happy hour for rapid transit in Montgomery County.

The forgotten landmark: The Washington Coliseum, formerly Uline Arena, is now used as a parking facility, but once hosted the Beatles’ first concert in America. To learn more about the facility’s fascinating history, join the District Public Library for the last spring edition of its Know Your Neighborhood series as it presents a screening and panel discussion of filmmaker Jason Hornick’s documentary “The Washington Coliseum: The Forgotten Landmark.” The screening takes place this Tuesday, April 8, 6:30 pm at the Northeast Branch Library, 330 7th St. NE.

Maryland Ave SW drop-in workshop: DC’s Maryland Avenue SW Small Area Plan hopes to knit back together the L’Enfant street grid in the Southwest Federal Center area. The plan calls for building a new Maryland Avenue atop the railroad tracks, between 7th and 12th Streets SW, which will link to existing roads, create new public spaces, and provide new walking, biking, and driving routes.

Following the study, the District Department of Transportation started its own analysis about whether it’s possible to build Maryland Avenue and delve into more technical detail. DDOT officials are going to be outside the L’Enfant Plaza Metro Station at 7th & Maryland Avenue SW on Friday, April 11, from 11-1 and again from 4-6 to talk to people about their findings. The rain location is the Marketing Center at L’Enfant Plaza (next to Sandella’s).

Happy hour for rapid transit in Montgomery: Interested in seeing Rapid Transit in Montgomery County? Join the Coalition for Smarter Growth and Communities for Transit at a happy hour next week, on Tuesday, April 15, 6 pm, to hear the latest news about Rapid Transit, how you can get involved, and to connect with fellow allies, volunteers, and supporters.

The event is at the Communities for Transit office, 8630 Fenton Street, Suite 500, in Silver Spring. The event is free but please register here.