Lane reduction is the key recommendation of the mayor’s panel, an idea that was also put forward in Regional Plan Association’s report last year. If we fail to realize this proposal, we are missing a critical opportunity to transform and streamline the BQE with a 21st-century design that would not only help New York achieve its goals to reduce congestion and carbon emissions, but that would be a more efficient, less costly infrastructure project.

Let’s take on the traffic issue first. Smaller highways don’t result in more traffic jams; they result in fewer cars on the road. It’s not unlike the experience of the new, successful 14th Street busway or the pedestrianization of Times Square. In both cases, encouraging the more seamless flow of traffic by de-emphasizing car-centric options in favor of public transit resulted in more pleasant street life without adverse traffic effects.

Historical examples in New York City, including closures on the Williamsburg Bridge in the 1980s and the total collapse of the West Side Highway in the 1970s, have shown that traffic is actually absorbed into the system, much of it funneling into public transit.

From a global perspective, cities across the U.S. and countries around the world are taking lane reduction to the end conclusion and eliminating outdated highways altogether. They are replacing hotbeds of pollution with walkable green spaces, all with no discernible negative impact on traffic but instead great benefits to the surrounding communities.

That’s exactly what Rochester did with its Inner Loop East Transformation Project and Paris with its Pompidou Expressway, which is now a riverfront “beach” and pedestrian walkway.

Of course, this isn’t just a traffic issue. A smaller BQE not only means less pollution with fewer cars on the road. It would provide an opportunity to reprogram the open space with additional parks, housing and other facilities that provide amenities to residents.

Beyond the benefits from a traffic and sustainability perspective, reimagining the BQE as a four-lane thoroughfare is a more fiscally responsible proposal than keeping the six-lane highway. The projected cost of fixing the triple-cantilever portion alone is $3 billion to $4 billion—one of the most expensive projects in the city’s capital program. We will only reduce costs by doing this in a more efficient way.

The decision is now in de Blasio’s hands. He assembled a group of experts, and they delivered for the city. We hope the mayor takes their recommendations to heart and lets the hardworking people at DOT do their job reinventing the BQE.

Kate Slevin is senior vice president of state programs at the Regional Plan Association, where Rachel Weinberger is a senior transportation fellow.