A proposal to convert two streets in Park Slope to one-way thoroughfares is making waves in the Brooklyn neighborhood, where residents say they worry speeding cars will put an end to their pedestrian-friendly environment.

The Department of Transportation this evening will present a proposal to make Sixth and Seventh avenues one-way streets, which they say will boost pedestrian and vehicle safety at sharp turns.

But because both avenues terminate at the edge of the Atlantic Yards footprint, residents are saying the proposal’s unstated goal is to prepare the neighborhood to handle the heavier traffic loads that are anticipated when the arena and residential tower are built. One-way avenues typically allow for more vehicles to drive faster than on two-way streets.

“Park Slope has a terrific neighborhood character,” Council Member David Yassky, who represents the community, said. “Sixth and Seventh avenues are crucial parts of that, and they shouldn’t be turned into highways to drive through.”

Mr. Yassky said he plans to speak out against the proposal at this evening’s community board meeting, where a vote against the proposal could kill it.

“If the community doesn’t support these proposed changes, we will not move forward with them,” a spokeswoman for the Department of Transportation, Kay Sarlin, said.

A petition against the proposal posted online by a community group, Park Slope Neighbors, garnered more than 1,100 signatures in less than 48 hours, according to the group’s founder, Aaron Naparstek.

Mr. Naparstek, the author of a book of haikus about traffic, “Honku,” and a trustee of the Park Slope Civic Council, called the proposal “classic 1950s-era traffic engineering.” The council has been papering the neighborhood with Mr. Naparstek’s “One Way, No Way” slogan.

“DOT would make adjustments to the traffic signal progression along Sixth and Seventh avenues and narrow the travel lanes on Seventh Avenue to keep vehicles from exceeding the speed limit,” Ms. Sarlin said.

“We’re hoping that tomorrow is the beginning of a process, not the end of a process,” the district manager of Community Board 6 in Park Slope, Craig Hammerman, said. “If we have a chance to work together, our experiences at the local level are invaluable to the DOT’s problem solving exercises.”

The transportation department will also present a proposal tonight that would narrow Fourth Avenue to four lanes of traffic from six.