Hard Telling Not Knowing each week tries to answer your burning questions about why things are the way they are in Maine — specifically about Maine culture and history, both long ago and recent, large and small, important and silly. Send your questions to eburnham@bangordailynews.com .

The solid line of cars snaked up Route 2, with both lanes of traffic reserved for vehicles heading northeast from Bangor to Orono. Buses, trucks and personal vehicles were all packed with people evacuating Bangor on a warm late spring day in the 1950s. Nobody was in any sort of danger.

It was all part of Operation Alert, a massive Cold War-era national training exercise to simulate how 52 different cities across the country would handle a bombing attack by the Soviet Union. In Bangor, the simulation was called Operation Scram, and on June 15, 1955, it saw thousands of people evacuate Bangor’s east side for points north. The Maine office of the Federal Civil Defense Administration coordinated the effort, in cooperation with local police, Dow Air Force Base, hospitals, schools and other organizations.

The scale of the simulation was unprecedented, involving thousands of civilians volunteering in order to see how smoothly — or not smoothly — the whole thing might go. The Maine Emergency Management Agency, the agency that in the 1980s succeeded Maine Civil Defense, shared a video earlier this month combining footage from the simulation held by the Maine State Library, its own research and q.