I've seen these signs around for the last couple of years and could never understand them. They're posted at a few regulated intersections, including on Summer Street in front of the Arlington Recreation Center. My best guess was that cyclists were expected to stop on green lights, which made no sense. The Boston Globe explained in yesterday's Starts and Stops column: when the light is red, stopping at the line should activate the loop sensor and change the light to green. But only if your bike has enough steel in it, as aluminum and carbon fiber don't count. The highway department has got to get better writers.
Today: 13 miles. This year: 671.5 miles.