This year has brought a whirlwind of autonomous vehicle news, with automakers announcing plans for self-driving cars and some presenting flashy concept vehicles. Tech companies such as Apple, Uber and Google are in the game, too. There are huge, disruptive changes coming.

For cities this creates both great opportunities and risks. Gabe Klein knows this well, given his history at organizations that move slowly (government) and quickly (start-ups).

Klein has led the department of transportation in both Chicago and the District of Columbia. He worked at Zipcar, and still advises mobility start-ups such as TransitScreen. He’s now a special venture partner with Fontinalis Partners.

In Start-Up City, published this month, Klein shares what he’s learned, and casts an eye toward the future. He identifies the advent of self-driving and connected vehicles as perhaps the greatest challenge and most exciting innovation cities will face in coming decades.

He speaks of the potential for better, safer cities with improved public spaces. With self-driving vehicles, there will be significantly less need for parking spaces, creating an opportunity to reclaim and optimize land. Accidents should be less common. Cyclists and pedestrians will be safer. The battle for the future of our ground transportation systems is one he welcomes.

“I can even imagine a scenario in which streets are designed as large, pervious surfaces that are not only more beautiful, breaking down barriers between sidewalks and roads, but can also help our cities become more resilient,” Klein writes.

He’s also concerned about what could be lost in these changes. Klein wants governments to collaborate with entrepreneurs on business models that increase access, safety and equitability. He warns there’s been little discussion of this to date, despite the opportunity for transportation policy makers.

“If this tack is not taken, there is a risk that these services left solely to the free market could instead reinforce existing stratifications, undermining public transit systems and making mobility even more of a luxury good,” Klein says.

He suggests the creation of design guidelines for the city of the future. They would focus on reclaiming public space, democratizing mobility and choosing quality of life over just time saved on efficient transportation.

“If governments don’t get their priorities straight and get this right, we will recreate existing stratifications and render people out of the canvas that is the future city,” Klein cautions.

Klein expects the best public transportation services to survive the disruptive arrival of self-driving vehicles, but he suggests some will not.

“Unreliable local bus networks and mediocre suburban and rural transit are ripe for disruption in this new world,” Klein writes. “Fundamentally this is because these services are extremely expensive on a per-ride basis and do not serve customers especially well in terms of frequency, speed, and overall experience.”

He calls for calculating the efficiency of vehicles per person, per mile, as well as their impact on the environment. An eco-friendly self-driving car holding four riders might make more sense than a half-empty bus.

As more public spaces open up, one of Klein’s ideas is “slow lanes.” Any mode of transit could ride in these lanes, provided it weighs under 500 pounds and doesn’t go over 15 mph.

A better tomorrow is waiting for us, but we can’t leave it all to the disruptors.