We’re redesigning our streetscape — but what if we’re getting it all wrong?

A proposed hotel tower in Kenmore Square.STUDIO GANG

A PROMINENT CORNER of Kenmore Square is being reimagined by a developer, but unlike proposals of the past, this one, by Robert Korff and the architecture firm Studio Gang, doesn’t just present sexy renderings of a shiny new tower. It also suggests an ambitious reconfiguration of Kenmore Square itself.

The entire project hinges on a complete re-routing of traffic to favor bicyclists and pedestrians, adding big swaths of public space in the process.

In so doing, the proposal echoes much contemporary streetscape planning. It squeezes down vehicular traffic on Beacon Street and Commonwealth Avenue, just like New York’s Times Square, where streets once filled with cars and trucks have been repurposed as pedestrian plazas. In Boston and Cambridge, several main roadways like Massachusetts Avenue have been retrofit in similar fashion, swapping curbside parking and travel lanes for brightly painted pathways for buses or bikes.

All very progressive and forward-thinking for a city of the 21st century. But what if such plans don’t adequately anticipate the future? Perhaps more than at any time, new forms of transportation are creating many unknowns.

For example, the imminent arrival of autonomous cars may allow narrower streets because driverless cars can essentially tailgate each other. Timed traffic signals, guided by artificial intelligence, will keep things flowing in ways far superior to the red light, green light system of today. Downtowns everywhere won’t have to devote prized urban land for big parking garages or surface lots.

But shared autonomous vehicles may also end up exacerbating Boston’s first-in-the-nation congestion problems. One study predicts that driverless Ubers and Lyfts will be in such continual use, circling the block looking for rides, key streets in major metropolitan areas will see more gridlock than ever before.

Other tech-driven vehicles will demand a different kind of street space as well, and we should be designing for them now. Shared electric scooters and delivery robots will compete for space alongside bikes and pedestrians. Trackless trams optically guided by GPS need flexibility to thread their way through congestion or accidents. Underground and overhead might be crisscrossed with urban cable cars and vacuum-tube hyperloops.

How to plan for the next technological leaps in transportation? Mayor Martin J. Walsh recently took an incremental step when he established drop-off zones for Uber and Lyft in congested areas around Fenway Park.

But it’s a big moment, and the pressure is on. Cities everywhere are spending time and money retrofitting the multi-lane highways prompted by the last technological revolution in mobility — the ubiquitous automobile. In Boston, that has meant burying the elevated Central Artery, and current plans to re-align the Mass Pike interchange at Allston.

To be sure, taxes and regulation can help — a penalty for ride-share vehicles driving with an empty passenger seat, sliding-scale tolls for peak times, higher fees for parking, and congestion pricing, now in use in London, Stockholm, and Singapore, and recently proposed again for Manhattan below midtown.

But if we want to prepare for an uncertain future, an emerging trend in the planning profession may hold better answers. A method known as exploratory scenario planning allows planners to map out multiple scenarios, leaving room for unknowns. When conditions on the ground indicate that one of the scenarios is more likely, that’s the trigger for going all-in on infrastructure, policies, and placemaking.

Scenario planning has a long history. Nearly 50 years ago, Royal Dutch Shell deployed a “what if” analysis before making massive investments in new infrastructure, like offshore well-drilling. Today, exploratory scenario planning is being used widely to prepare cities for climate change-induced sea level rise and flooding.

“It’s a better way to think about how the future might unfold,” said Janae Futrell, who manages the national Consortium for Scenario Planning, which aims to share the experience of planners using the approach. “It makes no sense to create plans as if everything will stay frozen in time. It wastes a lot of time and money to create plans that lack adaptive capacity; they have a very short shelf life.”

This more open-ended approach has another benefit: It allows more public input and citizen engagement throughout the planning process, instead of a hard-and-fast decision that draws outcry and complaints later.

Boston City Councilor Michelle Wu is a fan of scenario planning: “That’s exactly how we have to approach planning for the long term. . . by leaving it open for future generations to make changes, while still aiming for a sustainable, just and healthy future.”

When the city of the future is such a moving target, noted Wu, policymakers need to consider multiple future scenarios and above all, stay nimble: “When you’re implementing big planning decisions, you are setting the stage for what life will be like for people who haven’t even been born yet.”

That flexibility — in contrast to the unalterable urban planning that gave us so many highway viaducts — may be the most important guiding principle. The Kenmore Square proposal, as revolutionary as it is, might go through several versions in beta, testing out what works and what doesn’t, as technology advances. If conflicts arise, reconfigure.

It will be a lot easier to re-do pavement painting and stanchions, than to disassemble the last century’s concrete and steel.