New York City officials will take their streetcar campaign to Red Hook Thursday. They’ll have to be prepared to get everyone on board.

After a similar forum in Astoria earlier this month, some residents came away with incomplete information, unanswered questions and concerns that were not addressed. Some thought the streetcar was to be paid for with a tax increase, while others didn’t understand why the city wasn’t just adding a bus route.

Mayor Bill de Blasio’s plan would create a 16-mile route down the Brooklyn and Queens waterfront, where an electric streetcar would run along tracks flush with the road. It may include as many as 30 stops, and could run every five minutes during peak times. It might not open until 2024.

Even city officials don’t have all the details yet, and we’re only at the beginning of what is bound to be a lengthy process. But if the Brooklyn Queens Connector, as the streetcar has been dubbed, is to become a reality, proper community engagement should begin now. City Hall can win its case for much-needed alternative transportation with clear, complete answers to questions, while being flexible to planning and new ideas.

City officials say the $2.5 billion streetcar will lead to increases in property values along much of the waterfront and enough new property development to, in effect, pay for itself in tax revenue. Advocates say it’s better than a new bus route, offering more capacity, a greater economic impact, and a city-created alternative that doesn’t involve state or MTA approvals. The streetcar would connect communities, especially residents of public housing, to the rest of the city — connections that are now missing.

There’s plenty we still don’t know. Advocates like Friends of the Brooklyn Queens Connector, a group that includes former MTA heads Jay Walder and Joe Lhota, fought for the concept even before the de Blasio administration took it on. They promise social media campaigns and outreach up and down the waterfront. That’s important. Without community buy-in now, the bumps in the road may be insurmountable later.