Picture this: cars descend from apartments high in the sky to seamlessly merge onto highways. They move next to vehicles so narrow they might fit two to a lane on today’s roads. The highways lack barriers separating the direction of travel. There’s no need for rumble strips or warning signs.

These are some of the ways road infrastructure may change as autonomous vehicles (AVs) become more prevalent.

Science fiction has already provided glimpses of what an AV-dominated city could look like. Perhaps the best visual representation occurred in scenes from Steven Spielberg’s 2002 film Minority Report.

Nobody can accurately predict how AVs will drive change for drivers, but that didn’t stop us from asking AV proponents, transportation experts, and the mayor of Stratford, Ontario to share their prognostications.

Canadian streets may not look like the ones in Minority Report for a while, but they will likely soon begin a gradual change brought on by AVs

Infrastructure changes won’t happen overnight. “There will likely be a long period of time where we have a mixed fleet of both AVs and traditional vehicles that will require traditional infrastructure,” says Mike Barnet, senior project engineer, intelligent transportation systems for Ontario’s Ministry of Transportation.

“The goal will be to add as little as possible, in an effort to reduce costs for government.”

The idea changes will happen gradually is pretty widely agreed upon. “If deployment of autonomous vehicles relies to any degree on public sector involvement, it will be really slow,” concurs Paul Godsmark, chief technology officer of the Canadian Automated Vehicles Centre of Excellence (CAVCOE).

“If AVs work in existing infrastructure, within existing traffic, and no changes are needed, there’s less involvement of (and delay by) the public sector,” he adds.

Still, road infrastructure is everywhere, it isn’t going away, and it will continue to evolve, as it always has. AVs may drive some of that evolution.

For instance, some things may disappear over time. Consider the humble parking lot or garage, for instance. If people opt to get picked up and dropped off by autonomous taxis – instead of owning cars – will we need all the parking lots and garages that currently cover our land?

Even if people own AVs, their vehicles can park themselves in areas where land is cheaper, and stay there until they’re summoned. Meanwhile, land occupied by parking lots in urban areas may be sold for development, parks, urban farms or other uses.

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Curbside parking may also disappear. “We can consider converting inside lanes to bicycle lanes or wider sidewalks,” says Godsmark. A civil engineer by training, he notes that bicycle lanes don’t need the same pavement quality or construction depth as traffic pavement.

Smart, connected AVs might not need as much room to maneuver as human drivers. “Narrower lanes are one opportunity that may result from AVs,” Barnet suggests. “This could lead to increased lane capacity, which may reduce congestion.”

If “drivers” don’t need to park AVs, drop-off and pick-up zones in places like office towers and shopping malls become more important than parking. They must smoothly accommodate large volumes of arrivals and departures within short periods of time.

Vehicles may “talk” to infrastructure to help traffic flow more smoothly and safely. Traffic lights could time changes to best suit traffic conditions approaching the intersections where they’re located.

“The vehicle becomes a sensor that can communicate directly with a traffic signal,” so that it can “dynamically adapt to real-time traffic volumes,” says Barnet.

Similarly, pressing a pedestrian crosswalk activation button may cause approaching traffic to slow down well in advance so that pedestrians can cross safely while cars need not come to a complete stop.

As AVs become common on the road, many experts predict fewer collisions thanks to the smarts built into both the vehicles and the roads they travel.

“This will reduce our need for traditional intelligent transportation systems used for incident detection and management, such as sensors in pavement and highway message signs, that provide incident information and travel time,” says Barnet.

He lists other changes like the elimination of barriers separating directions of traffic. This would enable traffic authorities to change lane directions during morning and evening commutes as traffic volumes change.

If significant increases in connected vehicles overburden wireless networks, the promise of safe autonomous transport could be compromised. After all, latency isn’t an option; drivers can’t afford the AV equivalent of dropped calls.

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MCity is a simulated city in Michigan used by automakers to test self-driving cars; Stratford, Ontario’s mayor wants to make his town a real “living lab”

The mayor of Stratford, Ontario, Dan Mathieson, wants to get ahead of this potential infrastructure barrier. “We’ve laid over 80 kilometres of fibre(-optic cable),” in recent years, Mathieson says. “We’ve also built a Wi-Fi network covering the whole city.”

Mathieson wants AV makers and other technology companies to use his town as a “living lab” so they can glean practical insights. “Maybe we can help car companies realize what data should stay on the car and be sent only during off-peak times as opposed to clogging a network,” he says.

Regardless of whether a human being or a machine drives a vehicle, notifications about conditions on the road ahead enhance safety and fuel economy.

That’s one of many insights contained in Vehicle-to-Vehicle Communications: Readiness of V2V Technology for Application, a 327-page analysis of a vehicle’s ability to exchange information with both its environment and other vehicles, published jointly by the U.S. Department of Transportation and the National Highway Traffic Safety Administration.

The report suggests future infrastructure could warn drivers about upcoming situations like red lights; sharp curves; reduced speed zones; spot weather information; and railroad crossing violations.

Cars may well turn into infrastructure as well. Like the pace car on a racetrack that leads competitors in formation behind it, a non-AV driven by a professional driver might lead a caravan of AVs.

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Mercedes-Benz trucks involved a project like the Volvo-led SARTRE road-train truck-caravan program.

This describes Project SARTRE (or Safe Road Trains for the Environment), a European experiment meant to improve highway safety and environmental conservation without having to heavily modify existing road systems.

With all the smarts being built into roads and potentially added to infrastructure, is there still a role for human drivers?

CAVCOE’s Godsmark says he pictures a future defined by AV-only zones in urban centres and a mix of AVs and human-driven vehicles everywhere else, mostly for one simple reason.

“We can make roads more efficient once we remove the human driver.”