As part of the Newton-in-Motion transportation project, there is a demonstration of various Complete Streets ideas planned for Friday and Saturday, June 10 and 11th at Washington and Walnut Streets, weather permitting.  Complete Streets are designed to make the roadway safe and welcoming for all users, including abutters, motorists, pedestrians, bicyclists, and public transit commuters of all ages and abilities.  This demonstration has been postponed twice now, due to the use of water-soluble paint markings, but hopefully the weather will cooperate this time!
From the city website:

This 2-day event will provide opportunities to test out a temporary traffic configuration made of movable parts showing tactics like curb extensions, parklets, and buffered bike lanes. This project is intended to workshop how temporary transportation projects could be utilized in Newton and give everyone the opportunity to see what some of these tactics look and feel like in real life. Kids welcomed and encouraged to participate!