Even after metro Denver grows by another million people, today’s roads may have plenty of room for them — without the need for much more pavement.
Optimism in that seeming paradox has taken hold among some transportation experts and even local transportation planners. Their predictions depend on emerging technology that promises in coming decades to transform how people drive, eliminate most crashes and free up road space on a scale that was unimaginable just a few years ago.
Sound far-fetched? University researchers and the federal government expect self-driving cars to become common in the next decade or two and say those offer the greatest potential for reducing traffic congestion.
Even if that doesn’t happen so soon, the Colorado Department of Transportation and local agencies are testing or exploring new technologies, from better real-time road information systems to on-ramp access signals that adapt to conditions to smooth today’s bottlenecks.
“This new wave has the makings of being something that’s transformational,” said Douglas Rex, who directs transportation planning for the Denver Regional Council of Governments.
Experts agree more about the scale of that transformation — essentially marking a sea-change in driving — than on the details, including whether self-driving cars ultimately will reduce congestion as drastically as some hope.
The unknowns make it tough to make traffic projections that account for such large tech-driven changes. But Rex added: “We know it’s going to happen. It’s just a matter of when.”
With billions of dollars invested already, the most-advanced self-driving vehicle prototypes remain unproven in real-world conditions. But in testing, computers in control of those models are accelerating, braking, navigating and steering, theoretically removing the whims of accident-causing human impulses.
“Autonomous vehicles are really the only potential (large-scale) technological fix to the problem we have,” said Fred Mannering, a professor of civil and environmental engineering at the University of South Florida. He has long studied road safety and, in recent years, innovation in transportation technology.
“With our existing road system, you can get something like 10 times more capacity.”
On the horizon, he and others envision fast-moving flotillas of big-rig trucks. Self-driving cars will communicate with each other and travel with less space between them in all directions, with narrower lanes allowing more to be squeezed into the same freeway width. Smoother flow will be the norm as automation technology untangles traffic.
Without such drastic technology-driven changes, though, metro Denver’s traffic future could be bleak.
As The Denver Post reported in December, DRCOG’s projections — based on today’s conventional models — say that by 2040, the metro area’s growth from 3.1 million to 4.3 million people likely will extend and intensify the most congested periods of the day for hours.
Yet under forecast budget constraints, DRCOG expects $153 billion of the road maintenance and upgrade projects needed to accommodate that growth to be underfunded by one-third. The persistent gap in the state’s highway budget is among the hottest topics of debate in this year’s General Assembly, where Democrats and Republicans disagree on solutions.
Major automakers, university researchers and, famously, Google are working to lessen the sting of the depressing projections facing Denver commuters.
Money is pouring into the development of self-driving cars, which are starting to live up to the promises in low-speed testing — although not always without human intervention.
The U.S. Department of Transportation’s recent “Beyond Traffic 2045” draft report, intended as a “framework for the future,” predicts that self-driving cars will be commercially available within 20 years.
Last month, the USDOT announced its budget request to spend $4 billion over 10 years to accelerate their development.
How quickly driverless cars become reality will depend in part on the adaptability of the transportation system and state and federal regulations amid a minefield of liability considerations.
Federal agencies are sorting through some of those issues now. This month, the National Highway Traffic Safety Administration decided in response to Google’s request that computers that control self-driving cars would count as drivers for regulatory purposes.
“If you look back 20 years ago, we couldn’t imagine a solution like this,” Mannering said, adding: “I’m not saying in 20 years all vehicles will be autonomous, but the potential is enormous, unlike anything that we’ve ever seen.”
Self-driving cars would take away much of the stress of commuting. Some prognosticators envision next-generation, Uber-like car services run by business or government that would negate the need for ownership — or so much space devoted to parking.
Bill James, who represents much of Denver on the Regional Transportation District’s board, said RTD’s newer rail lines may long serve their purpose, but he could imagine a future where bus lines are replaced by smaller, self-driving vehicles picking people up on demand.
“Ultimately, what makes the most sense is for not everybody to own their own vehicle, because they’re going to be shared,” James said.
The self-driving future faces plenty of hurdles. Not all drivers will want to give up control over the wheel. And some experts say there’s the potential for self-driving cars to spur more trips or alter traffic patterns in unhelpful ways.
A recent study found that in simulations of movement at intersections, involving a mix of driverless and regular cars, slower travel might result because of how smoothly, and slowly, the self-driving vehicles accelerate.
Aleksandar Stevanovic, an associate engineering professor at Florida Atlantic University, is among skeptics of the idea that self-driving cars will relieve congestion.
“They may release drivers from driving tasks and give them opportunity to efficiently use their commuting time for something else,” said Stevanovic, who’s director of FAU’s Lab for Adaptive Traffic Operations and Management. “Thus, as a result … we may have even more congestion but we may be less concerned about it.”
On the other hand, Carlo Ratti, director of the Senseable City Laboratory at the Massachusetts Institute of Technology, cites research projecting a steep drop in the number of needed vehicles in cities as more are shared, offsetting any slowdowns.
Short of self-driving vehicles, some new cars already sport the kinds of components that eventually will make them reality. Those include cruise control that adapts to the speed of the car ahead, crash-avoidance braking systems and, now in Teslas, automated highway steering.
“To go from those technologies to an automated vehicle completely is not a huge leap, from an engineering viewpoint,” said Kevin C. Desouza, an associate dean and professor at Arizona State University’s College of Public Service & Community Solutions. “Most of the leaps have already been made in terms of making cars more intelligent when it comes to preventing collisions,” especially in higher-end vehicles.
Transportation agencies in Colorado and elsewhere, meanwhile, are installing more sensors and systems on roads and freeways that eventually will allow cars with the right features to transmit and receive real-time road and traffic information — better than Google’s maps app or your navigation system provide now.
And some cities are looking at installing a new kind of smart traffic signal. Rather than requiring a human to set the light timing cycle at an intersection, the new signals monitor traffic sensors. As patterns change, they self-tweak cycles to keep vehicles moving as much as possible — and communicate with nearby signals.
In Denver, the Department of Public Works hasn’t installed any of those “adaptive” signals yet, but it can now remotely reprogram 90 percent of its 1,250 old-school traffic signals. Its workers also know quickly when signals malfunction or lose power.
Aided by a new partnership with the Rocky Mountain Institute, the city is looking at new technology to make more real-time information available to drivers. And the city is making plans with neighboring suburbs to connect their data systems, along with CDOT’s. Connected systems would provide both transportation managers and drivers — on mobile devices or in-car screens — with an even clearer picture of congestion minute to minute, said Steve Hersey, Denver’s city traffic engineer.
Such efforts are laying the “electronic breadcrumb trail” that will aid automated cars years from now, said Peter Kozinski, who heads CDOT’s new future-looking RoadX program.
“They can follow it, and people can gain back some of the time that they lose by being frustrated and stuck in congestion,” he said.
CDOT has charged RoadX, which it launched in October, with the task of finding viable alternatives to highway expansion to unclog Colorado’s roads.
Program leaders plan to launch pilot projects for two interstate corridors in the next year or so. They also are seeking out companies to test out their new technology in the state.
In the heavily traveled Interstate 70 mountain corridor, CDOT plans to spend $10 million over two years to equip about 700 state, commercial and shuttle vehicles with short-range radio devices. They will transmit live road conditions and other information to CDOT, which can then broadcast alerts to other drivers through a phone app.
Separately, the same corridor was picked in January by HERE, a mapping service backed by European automakers, for the first North American test of similar “connected vehicles” technology. Kozinski says 1,000 frequent I-70 mountain drivers will be recruited to use the smartphone-based service, which also will expand CDOT’s live information-sharing and alert capabilities.
In the southeast Denver area, CDOT is planning a $7 million conversion of on-ramp meters — the red and green lights that intersperse entering vehicles during busy times — to a “coordinated ramp metering” system.
Modeled on a system developed in Australia, the pilot — the first of its kind in the United States — will focus on Interstate 25’s northbound on-ramps between Ridgegate Parkway and either Colorado or University boulevards. The new signals, linked to freeway sensors and to one another by computers, will automatically adjust the length of on-ramp wait times based on how congested I-25 gets.
For drivers lined up to get on, the system could mean a longer wait, Kozinski says.
In return for that trade-off, CDOT has high hopes: It’s projecting the system will improve I-25 northbound’s traffic flow by at least 25 percent. In Melbourne, Australia, the first test of that system in 2008 increased speeds by an average of 41 percent.
“You can either wait now or you can wait later,” said Shailen Bhatt, CDOT’s executive director. “But if we can reduce traffic congestion by 25 percent and squeeze more congestion through the bottle, it’s better for everybody.”
Such efforts might seem, to some, like Band-Aids in the absence of more robust — and costly — road-widening.
But Bhatt and other transportation leaders say they are necessary groundwork to lay while road and vehicle technology develop.
“We are having that conversation (about what) technology means for some of these 25-year plans, 30-year plans,” Bhatt said. “That is the one thing that gives me some hope here. … What has often happened in human history is that what seems to be very bleak is then helped by technology.”
Jon Murray: 303-954-1405, firstname.lastname@example.org or @JonMurray
About the series
The Denver Post this year is examining the ways that increased traffic congestion is affecting drivers and residents — as well as plans and potential changes that could ease the crunch and expand transportation options. The first story, in December, looked at traffic and population growth projections that could bring worse congestion to the metro area in coming decades.